I accidentally used a bathroom sponge on my dishes

If your dishes are ceramic, you could put them into a pot, fill in water and heat up until boiling and switch the fire off. Later turn cooler take them out, then use 70% rubbing alcohol to wipe your dishes, then finally wash them with clean water thoroughly.

Any regular or special cleaning method should do the work to get rid of those dirtiness or adhered bacteria. However if you still have concern about the dishes, maybe just abandon or not use them and remember to separate bathroom's and kitchen's sponges completely, and DO NOT misuse again. Prevention is always better than a cure.

I mean, I wouldn't eat off them like that. I suggest washing them with regular dishwashing equipment first.

Your dishes aren't ruined or anything. A big reason they're made out of something non-porous, like ceramic or metal or plastic, is so you can scrub them clean with soap and water without any food or, uh, other stuff getting stuck inside them. The scrubbing clears off any macroscopic dirt, and the soap both rinses off microscopic stuff and kills a lot of microorganisms. If cleaning dishes with normal methods weren't enough to get rid of dangerous germs, a whole lot more people would get food poisoning.