I want to use some oil to lubricate my bearings in my baitcasting reels and have a bunch of little oil bottles that came with my shimano and abu garcia reels. Are these good enough quality or should I purchase another brand of oil?

I can't speak about the Abu oil, but the Shimano oil is perfectly fine to use in your reels. I've got to assume the stuff that comes with an Abu reel is of similar quality.

Shimano Bantam Oil is some of the best stuff around. It's probably best to stick with OE oil, unless you completely clean out the bearings.

I've used both and they work just fine. I toss those little bottles in my tackle boxes and boat.

The oem oils are fine. The fact that that you are maintaining the equipment is far more importatnt than lube brand.