On the chatbox, some usergroup are able to use the command called "/team" (usergroup parameter in the vbulletin options for the chatbox).
The chat sent with this command are shown in the Team channel
I have done this coz when lots of people speak in the day you might miss some important team messages. So with the separation of the channels, this problem is solved (I plan to do an alert in the next version which tell the user that a new chat has been sent on this channel).
However, user are not obliged to you the /team prefix for their messages when they are located in the team channel.