I looked at 680 and I am not sure how an above ground pool light gets relief from any of the 680.23 and 680.24 rules. We don't see much "above ground" here and I have never wired one of those lights. You should probably take a peek and see what makes sense with what they gave you.
I think you are going to be "equipotential" bonding with some #8, laying conduit to the house and buying a listed junction box. Also note that your insulated #12cu EGC shall be unspliced to the J box.
If this thing has a cord cap on it they must be in another article in the code I don't know about.
