I think that maybe too much is made of Peter going to the Jews only and Paul only to the Gentiles.
It was Peter who first went, at the instigation of God, to convert a group of Gentiles (Acts 10-11; 15:7); and of course, in almost every place that Paul visited, he made a bee-line for the local synagogue if there was one. He persisted in this practice even after declaring that he would go to the Gentiles (Acts 18:6; 19:8).
It seems to me that the arrangement described in Gal. 2:9 was simply that Paul and Barnabas should continue their mission to the Gentiles while the apostles carried on mopping up Israel and Samaria. But things may not have stayed like that. There is no mention of Peter or any other apostle when Paul returned to Jerusalem in Acts 21, and Acts 21:18 suggests that James was the most senior leader present; and Church tradition (which we don't necessarily trust) places Peter in Rome at some point, John in Ephesus and Thomas all the way over in India.
Martin, prophecy and history demonstrates that Israel had a 40 year window to enter into her rest. We learn that from more than one passage, not the least of which is Hebrews 3. This means the apostolic era and the nation ended at the same time and through one event, the dispersion. Look at the parable Jesus gave which was also a prophecy from foreknowledge. This parable is a prophecy of this whole age. Follow the logic.
Matt 23:1 And Jesus answered and spake unto them again by parables, and said,
2 The kingdom of heaven is like unto a certain king, which made a marriage for his son,
3 And sent forth his servants to call them that were bidden to the wedding: and they would not come.
4 Again, he sent forth other servants, saying, Tell them which are bidden, Behold, I have prepared my dinner: my oxen and [my] fatlings [are] killed, and all things [are] ready: come unto the marriage.
5 But they made light of it, and went their ways, one to his farm, another to his merchandise:
6 And the remnant took his servants, and entreated them spitefully, and slew them.
7 But when the king heard thereof, he was wroth: and he sent forth his armies, and destroyed those murderers,( those murderers were the ones bidden, Judah and Jerusalem) and burned up their city.
After the burning of the city he goes to those who were
not bidden.
8 Then saith he to his servants,
The wedding is ready, but they which were bidden were not worthy.
Martin, I do not believe there is maybe more than one or two posting on this whole site who believes that the wedding was ready and planned for the same time their city was burned up because they would not come to the marriage.
9 Go ye therefore into the highways, and as many as ye shall find, bid to the marriage.
10 So those servants went out into the highways, and gathered together all as many as they found, both bad and good: and the wedding was furnished with guests. (the guests would be the bride)
Now, since there are no guests an effort must be put in place to find different guests and gather them to the wedding. These are not the cultural elites and some came in without a wedding garment. They were thrown out and burned up. They represent the unsaved church members. Read on in the parable and you will see what I mean.
11 And when the king came in to see the guests, he saw there a man which had not on a wedding garment:
12 And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was speechless.
13 Then said the king to the servants, Bind him hand and foot, and take him away, and cast him into outer darkness; there shall be weeping and gnashing of teeth.
14 For many are called, but few are chosen.
There was no word ONLY to the Jews or ONLY to the gentiles with Paul and Peter. Each of their callings was ministering to them. It did not mean they were limited to that group of people.
As a matter of fact Peter was given the keys to the kingdom and he used those keys to open the door of faith to the Jews in Acts 2 and also he opened the door of faith to gentiles in Acts 10. This precise language was even used for the action.
Read the contexts of these verses.
Mt 16:18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
Ac 15:14 Simeon hath declared how God at the first did visit the Gentiles, to take out of them a people for his name.
Acts 14:27 And when they were come, and had gathered the church together, they rehearsed all that God had done with them, and how he had opened the door of faith unto the Gentiles.