If a Jewish person accepts Jesus is he raptured with the Gentile believers?
In the Church body there is no distinction between Jew and Gentile (Galatians 3:28), so there is no benefit in one identity over another. For someone who believes in Messiah, being counted Jewish (or not) is meaningless. So Jewish people believing in Messiah are part of the Church and will be raptured with the Church.
GALATIANS 3:28 There is neither Jew nor Greek, there is neither slave nor free, there is [a]neither male nor female; for you are all one in Christ Jesus.
Additionally, for an in-depth explanation of your question, we suggest listening to our Galatians Study, specifically Chapter 2.