Are you sure the score was ever released? I don't see any releases for it, just the soundtrack: "Robert Folk" "Bachelor Party". Lots of scores never get released. It's up to the studio that commissioned it whether to release it or not.
Not to my knowledge, I do recall an old bootleg of it from like 10 years ago, here is a link to what i am talking about:
http://90ie.ru/11/bachelor-party-score-and-extended-soundtrack-malchishnik/
Honestly though, I am shocked that this is so hard to get as this score was done right after Folk did Police Academy and all the scores in bachelor party sound like an extension of that. Not to mention this is one of Tom Hanks first films. I honestly would love to get my hands on this score, i know there is a blu ray release out these days but can't confirm if there is any isolated scores that can be extracted, if so ...i would love to have them, or a good rip with vocals removed/SFX will do too ... but yes would love to see LaLaLand or some soundtrack label put something out of this ... highly one of folks most underrated scores ...and one of his earliest. Would appreciate anyone's help ... this needs to be out there, lol!