Messages Server-How do we group chat?

I am so confused on how to get this working, especially since it used to be so easy in iChat.

I want to be able to do group text chatting using Bonjour with Messages.app client. My recent understanding (now that I know Messages won't do it exept for video and audio) is that I have to enable our Messages service on our Mac Mini server. I can't get that to work either.

Any tips folks? What's your config between client and server to get this working? I can't create any groups in Messages.app client. This is so perplexing.