Peilcan.
The relevant authority in the Philippines is the "EXECUTIVE ORDER NO. 209, THE FAMILY CODE OF THE PHILIPPINES July 6, 1987" as amended by RA 8533 and subsequent RA"s.
Check the "Chan Robles Virtual Law Library" online for the above and all its amending Republic Acts. (There are quite a few amendments.)
Basically, it boils down to who divorced whom.
1. If a foreigner petitioned for divorce from his Filipino spouse, the divorce is recognised in the Philippines and the both can remarry and any subsequent marriage is recognised in the Philippines.
2. If the Filipino petitioned for divorce, the foreigner's divorced status is recognised and they are entitled to remarry,, but the Filipino is still regarded as "legally" married, by the Philippines law.
3. If a Filipino divorces a Filipino (overseas obviously) then the divorce is not recognised by the Philippines and both are still recognised as "legally" married by the Philippines Law.
Not fair? Bills are, and have been for a number of years, under discussion in the Philippines' Congress to level the playing field but, AFAIK, have come to nothing.
Best to get proper legal opinion. Preferably from at least two attorneys specialising in Philippines' Family Law, as there are some shyster lawyers out there who will tell you anything you want to hear, as long as you ante up the money.
Peter