you can queue other BGs in a raid, but ironically the larger BGs you can only queue as 5 or less with the built in system. The Preform AV enabler mentioned earlier makes it possible, but a bit less reliable. You have to be careful before you click "join" as it doesn't guarantee that ll the toons will get into the same BG. It's not that bad. I often run with some guildies, or some pocket healers and use the addon all the time. IMO its a dumb limitation. I hope when they make rated BGs that you can queue in a larger group.

on my BG theres this group that does "cross realm premades" and it messes it up for everyone else, because they get 40+ people all queueing for AV, along with the regular people queueing, and if they dont ALL get into the same one, they leave the queue and start over, BUT the way the system works now is that it wont start an AV until there are 40 ppl in queue, so what happens is, AV starts with like 15-20 ppl on one side, which is almost always a loss. People start to trickle in, but usually its too late. On top of that the premade people actively attempt to boot all other players not in their group, by standing away from the entrance, and marking everyone else AFK right at the start, to free up spots for the rest of them (they organize this over Vent so to keep stuff out of /bg chat.)