Mrs H
It is now quite apparent from all of the postings on this subject that there is no easy solution to this issue. There appears to be a consensus that there is no way to police the issue of pool usage and the by laws in which the community charges were laid out make it clear that villas are stand alone properties, the owners of which do not pay community fees, other than for refuse collection, security etc. whether they like it or not.
The sensible approach for you and any other villa owners who are serious in their desire to finally conclude this matter and get proper advice rather than personal opinion is for you to contact the administrators for Phase 1 and 2 and the other comnunities ie info@housingcomunidades.com
You will get proper advice rather than conjecture on whether it is a possibility for you to pay community fees to include the costs of pool maintenance in the Phase 3 Apartment community or not as they are the only people who can say whether or not this can happen. The other AGMs will have no bearing whatsoever on Phase 3 so you are most likely going to have to wait until your Communidad is formed to raise this issue for full approval of your community but again the best place for real advice is the administrators and not the forum.