I use Cytosport Muscle Milk (no creatine) twice a day, and have not ever had problems... In fact, I've only noticed that the trips are a little more snappy and much more comfortable and calm when I regularly exercise, and the stuff helps my body recover to a healthy, relaxed shape so well that I do not prefer to take psychedelics if I have not been keeping myself in shape. The difference is incredible
I would recommend, though, that you be safe and considerate of your health. Creatine doesn't really do much for your health and size in the long run (when compared to, say, just some muscle milk and a good workout)... but it will have negative effects after a while (say what you want, it always happens, you can't hide from reality). If anything, you should notice rampant muscle tension, irritability and hormonal imbalance... I don't know how well that might work for you in the clutch-play of hyperspace.
As always, supplements with Nitric Oxide are never safe, especially when used with psychedelics. The increased risk of bubbles and anuerism is nothing to play with. That'll put you out for good before you know it... if nothing else, the increased bloodflow while on DMT would really be hard on your scrotum and testicles, as if NO wasn't bad enough already.
Long and short: You may end up not liking the whole creatine + DMT thing for obvious reasons. If you're looking for something that will support you but still keep your body functioning naturally, a regular ol' amino acid/nutrient compound such as original Muscle Milk will provide the benefits you want (other than the creatine surge), without the creatine. It's even totally fine to use with Ayahuasca, and greatly limits vasoconstriction and cramps with LSD.
Either way, Happy Trails!