Hi onats,
Zambales is on the west side of the Philippines. Been there with my girlfriends a couple of times during the southwest monsoon, but we have'nt caught a single descent wave to ride. It's either big close out or 1 footer. Waves are inconsistent. Access is also difficult if you're commuting.
La Union is still the best spot for me. Cool place and (cute)locals. You can even check other spots up north if you want.