Phil is a professional when it comes to working with other musicians. He could tailor his work to whatever he was hired to do. I think it's more of Jon working the way he does with the people he does, I doubt Jon actively avoids Phil when writing songs but it maybe has more to do with him not being needed at that point in the process yet. Phil has been asked about the writing and his answer is always that the stuff he comes up with is too crazy for Bon Jovi, and then he goes and co-writes and records with Darius Rucker 😅😅....