Why do you want to get off clindamycin and tretinoin? I understand not wanting to be on antibiotics long term, but are you having bad side effects with the creams too?
I would personally try to get off antibiotics first and keep the creams going, just in case you break out from going off the antibiotics, at least you have some topicals to help get you through it. In my opinion, it never seems safe to "wean" off an antibiotic as they are prescribed in that dose for a reason. I have read logs of people who took their pills every other day or something and slowly space it out like that, but I would be wary of the side effects. You can also try to supplement that with a very strict and healthy diet if that's not something you're currently doing.