I'm not a bartender, but I have many friends who work for TR. I seem to remember it's the same union as grocery store workers? Am I crazy? I know we have some theatre bartenders on this site. Maybe they'll pop in.
Ushers are IATSE, as are a lot of theatre employees, but there are different locals. I'm assuming since the OP asked for more besides "the obvious ones" this kind of detail is required as opposed to just saying IATSE.
I did find this listing of theatrical unions on the Equity site which looks pretty complete: Actors' Equity Association American Federation of Musicians Local 802 American Guild of Musical Artists Dramatists Guild IATSE Local 1, Stage Hands IATSE Local 306, Ushers and Ticket Takers IATSE Local 751, Ticket Sellers IATSE Local 764, Wardrobe IATSE Local 798, Make-Up/Hair IATSE Local USA 829, United Scenic Artists IATSE Local 18032, Association of Theatrical Press Agents and Managers IUOE Local 30, Operating Engineers SEIU Local 32BJ, Theatre Division [I believe this is the bartenders] Society of Stage Directors and Choreographers Theatrical Teamsters Local 817 IBT.