It depends. The drywallers around here do it all. They don't like to follow up taping on someone else's shabby drywall job. Otherwise either one can put on the corner bead and if you use the new style with paper edges that are embedded, then the taper has to do them. Ask the tapers you are getting bids from. I don't blame you and in fact I recommend that most people should hire out the taping as that is an acquired skill that takes time to acquire.