Someone makes these for me, and when I was putting some on some Ballistic Nylon and Polyester bags, they used Supertek Sublistop. I don't know who makes it but it has a black back to block this "bleeding".
At any rate, I had to remove one that went on crooked, and it came off fine. I assume that you do have to keep the chemicals away from the actual print to prevent the transfer inks from running onto the garment and ruining it that way though.
Otherwise, the usual transfers (I don't know what brand) also say that they are fine on Poly but do suggest lowering the temp slightly.