DS has taken ebm and bits of formula from a NUK bottle since about 6 weeks (now 6 months) and I've never had any trouble getting him to move between breast and bottle.
Even when he was very fussy at the beginning, and I had supply issues (from being told to top-up at 2 weeks), the bottle never added to the problems (if that makes sense!!)
I did feed him with a syringe until 6 weeks, though.