it seems that syncevolution does not work very well on the phone (syncs too many things), but the N9 syncml sync framework is supposed to be hackable.
So, what you can possibly do is use syncevolution (on your phone, or a server) to make a bridge between syncml (N9 side) and carddav (server side).
Sadly, I absolutely can't help you with that, but if you make it work, please share