Hi Adrian.
I have lived here in the Philippines for the past 14 years. There are GT's all over the place, but in small numbers and size for the most part. There are a smattering of better GT's caught every year, usually from trolling or fishing live baits. There are more than a few avid popper and jig fishermen here, myself included, but our results show little hope, with only one fish I know of 30kg taken on popper in the last 5 or 6 years and one other of about 15kg, with another two or three taken on jigs . Batanes Islands up the far north seems to be the best bet, but is very weather dependant. It is incredibly frustrating because the waters are perfect, with some truely beautiful places and promising signs, but very overfished and bombed out, literaly. You will also have a great deal of difficulty getting fishing here arranged unless you know someone here with a boat who will help you. My advice would be that if you come here for a holiday, then enjoy the thebeautiful country, the people and their hospitality, but forget the fishing unless you are happy just to be frustraed on the water. I get my fix by travelling to Australia and fishing with Nomad every year. Every time, every day, more caught in one day than all my time in the Philippines. Actually as yet, I have yet to catch a fish here on popper, or jig, and I have my own boats!