In my understanding, the polarity of the magnetic field of a bipolar stepper motor does not matter. You can hook it up to the biploar driver either way and it would still work correctly. However, is there a drawback to reversing the polarity of the magnetic field by hoooking it up incorrectly?
It technically doesn't matter. Bipolar stepper motor drivers need to be able to drive current in either direction through the coils. However, I assume that you'll be using some off the shelf stepper driver, and if it just takes DIR and STEP inputs, by wiring it up in an arbitrary matter your motor might not step properly, that's all.
If it's the four-wire kind, you can't really hook it up backwards. Both coils are designed and intended for current to pass in each direction. In fact, to get rotation at all requires periodically reversing the direction of the current first in one coil, then in the other.