I take 2 caps dym extreme 30 minutes after my training and cell-tech immediatelly after training and I don't think it effects creatine absorption because sometimes in the morning I take a serving of cell-tech with 2 dym extreme and have no problems.
By the way caffeine has never been proven by real life athletes that it decreases absorption, it's just a myth. Only very few studies have been made and it means nothing.