Let me add, the just because you use a drill press..... doesn't mean the hole will be "ok", if you make them with a standard drill. There's flex, and there's also no guarantee things will be perfectly centered. The better way is to plug and redrill, using a drill press if you have one, or a hand drill with a guide to keep it square if you don't.
Not sure how much bigger the bushing holes need to be, but.... using a small sanding drum on a Dremel may be all you need, if you work the hole evenly and slowly. Well before you have a drop in fit, you'll have a fit that will allow starting into the hole, and while the hole wont be perfect, you'll be able to press or tap the bushing in, letting the compression of the wood make up for any slight differences. Bushings are fluted, to take advantage of wood compression on installation.
On another note - I usually run a sanding disk into the Warmoth made holes for TOM and stop-bar. I find their holes just a little too snug for my own tastes. The sanding drum method has never given me grief on that.
How about some more info, saying what size you have and what size you want to end up with.