Chrono Symphonic focuses only on Chrono Trigger.
Site Projects work on a game by game basis. Someone (or a group of people) come up with an idea for a project, and foster interest and participation by remixers, artists, and fans.
In other words, if you want a Chrono Cross project, you should try to organize it yourself.
I would, but I have no musical talent other than my turntables.
Who said you needed musical talent?
Well, you at least need to be known and respected in the community for people to follow you... Stick around, grey; maybe sometime.
If's it crap about the game, I'd be world famous.