The effects will be long term as higher temperatures increase the rate of their metabolism, amongst other things. Given the species you have, I would personally keep the tank at 25 C, but that is a personal choice and a compromise for both species. There are other potential problems with mixing species as you have, amongst which is water parameters, activity level, set-up requirements, etc. WCMM are one of the species that normally have better colouring in cooler water. What's done is done, and unless you plan to split them up, you are still probably providing better care than either species would be receiving in the average home, which is saying something about the poor averages. On the other hand, if someone were to offer to take one or the other off your hands for a perfect environment, then I would consider it seriously.
Regardless of the above, what I would really base my opinion of your care for the welfare of fish is whether you would seed and fish-less cycle or fish-in cycle your next tank as ammonia and nitrite poisoning have considerably more effect on the long-term welfare of the fish than water parameters that are a bit off.
