Does playing for the POST sport team affect career progressions and promotions?

I did in San Diego in 1970, and it got me recognition by base brass. That's a good thing, especially when we won.

Can go different ways. I played on the football team at Camp Lejeune which was a great time being a low ranking lance corporal at the time playing in a league with higher ranking officials kinda broke me in to how the marine corps works. Then turn around to playing Softball as a SSG at Fort Dix for 2 years had its ups and downs. Lots of crazy stories with that team.

Makes for a good bullet on your NCOER, but that is about it.