Well, for general fanart I might recommend groups like
Circle-of-Magic-Fans,
Tamora-Pierce-Fans or
Legends-of-Trebond. My reasoning is this: TCP goes through very long periods of quiet because it's more of a single event (stretched out over months) group. So I couldn't guarantee that the galleries here would get consistent views. The fandom for Tamora Pierce's work is surprisingly interconnected here and on other sites.
An invitation has been dispatched, you are most welcome to join.