Miller beers are proudly union made! they are organized under the UAW (United Auto Workers) . This means all the Miller beers (miller lite, etc). You can see the whole list here: http://www.uaw.org/uawmade/beer.cfm
Also, I just remembered, Full Sail Brewing Company is a worker-owned collective. Here's their website: http://www.fullsailbrewing.com/
anheuser busch is union.
PBR is union made as well. Also, craft brew fans don’t despair, Mendocino Brewing Company workers have organized with the Brotherhood of Teamsters!