Bass, rock bass, sunfish, trout and really all freshwater fish get parasites. ( salt water fish do too.). Yellow grub the kind of worm (cyst) you're probably referring to. They are supposed to be harmless to people even if you're eating raw fish. I cut them out of panfish when cleaning. If there are too many, I don't eat the fish. (Too much "ick" factor for me.). I've only seen that in two out of many hundreds of pan fish. You only find a yellow grub cyst once in a great while at least in the lakes and streams I fish. Go ahead and enjoy your rock bass like any other panfish.

Grease hot enough to fry fish will neutralize any parasitic grub or larva in the fillet.

Typically the ones I caught never yeilded enough flesh to make it worth it, but go for it!