As long as the Poly pool is not at capacity, you can pool hop there as a member staying on points. The beach is right there next to the pool so I would think no problem as long as it's not crowded.
We pool-hopped to the Poly on our last trip and really enjoyed it. We went to MK in the morning, stashing a little bag in the lockers there. Later that morning we grabbed our bag and took the monorail over to the Polynesian. Very nice pool with a nice slide down the volcano.