There have been pictures of the Vuolos with Mac. So, Jeremy has probably already shown off his pocket squares and pics of John Calvin's bust in his study.
After all, Mac's church is letting Jeremy live in a very nice house rent free and may be letting him matriculate for free in exchange for publicity on the show (and yes, Jeremy has mentioned The Masters Seminary by name). That said, I don't think Jeremy is holding up his end of the bargain. He only references church, not GCC by name.