Creatine is best taken in the preworkout. I've been thinking of doing that but my preshake has BCAA's and Glutamine. To my knowledge glutamine and creatine use the same transporters.
I wouldn't worry about the "same" transporters.
The glutamine isn't going to make it past your gut, let alone your liver. Orally taken, L-glutamine is never going to reach your muscles. The Supplement FAQ has a lengthy explanation about this.
So take your creatine with this preshake, it's going to be just fine