excerpt from Question #2 at the page linked below:
If we go to Acts 15, we read that there was a lot of debate in the Church about whether Gentile converts needed to be circumcised. After the debate, Peter “rose” and declared that circumcision was not necessary. James was not even in the picture at this point. Peter made an authoritative decision about the doctrinal question, and no one questioned him. In fact, after Peter spoke it says “all kept silent.” When you read the Greek phrase, it is in the aorist tense, which means the silence was the effect of Peter’s definitive teaching.
After Peter settles the issue, Paul and Barnabas speak in favor of Peter’s teaching. Only then does James come in. A few things about James’ discourse. First, James was the bishop of Jerusalem during the council, and it is common for a bishop to speak in favor of the pope’s teaching at a regional or ecumenical council. This is what James does. He agrees with Peter’s definitive teaching. Second, James begins speaking, not about the doctrinal issue, but about whether the Gentiles should obey the Noachide laws. At the end of James’ speech, he says “it is my judgment.” The Greek here (ego krino) means that James was giving a personal opinion about a pastoral issue, and recommends that the Gentiles obey the laws of Noah so as to more easily fraternize with the Jews.
So we see that Peter is the one who rules definitively on the question of doctrine, and all kept silent. His bishops then spoke in favor of his teaching, acknowledging that Peter was indeed the authority in the Church. No one questions Peter’s judgment. Then we have James who speaks in favor of Peter’s teaching by giving an opinion on a pastoral issue. Hardly a challenge to the authority of Peter. You should also point out to your friend that Acts 15 disproves the doctrine of sola Scriptura. If Peter would have relied upon the Scriptures, he would have concluded that Gentiles had to be circumcised, since all the Patriarchs and prophets were, the apostles were, and even Jesus was. But Peter, by virtue of his authority, decides the issue as the chief shepherd of the Church (and the decision was not based on the Scriptures).
http://www.scripturecatholic.com/church_qa.html
Interesting way James addresses Peter in verse 14. He does not even address Peter by the name the Lord gave him at the time he was supposed to be made head of the church and vicar of Christ. He calls him Simeon, not Peter. Evidently, James did not understand the Lord to have given Peter this pre-eminence, so did not call him Peter, but Simeon.
The assembly kept silent as they listened to Barnabas and Paul. It wasn’t all about Peter, much as Catholics would like to believe.
http://bible.cc/acts/15-12.htm
http://biblos.com/acts/15-12.htm
In the Council of Jerusalem, Peter plays almost no role.
No matter how you slice it, you can’t justify the papacy by using Peter’s role in the NT church as evidence without wholesale twisting and mangling of the Greek.
FYI James is nowhere called a Bishop, nor is Peter. In fact the title "Bishop" is not identified to any of the Apostles.