According to the article Cebu, a Port City in Prehistoric and in Present Times,
The Visayan Islands had earlier encounter [sic] with the Greek traders in 21 A.D.
This is repeated in the Wikipedia article Prehistory of the Philippines almost word for word but with a specific reference to the island of Cebu, 'discovered' in 1521 by Ferdinand Magellan who died there at the end of a bamboo spear. The same sentence also appears in History of the Philippines (900–1521).
The original source for all the above is a 1973 book History of Panay by Felix B Regalado and Quintin B Franco. A review of this book in the Journal of Asian and African Studies (1980) is less than complimentary in parts, notably:
the book is interspersed with a number of careless, trifling assertions
The reviewer also (rather uncharitably) describes the authors' English as "deplorable".
Unfortunately, despite being in the Philippines, I can't get my hands on a copy of this book to see from where the authors got the information about Greek traders in 21 AD. Nor have I been able to find any other clear reference to these Greek traders.
According to Jose Rizal (national hero), on Ptolemy's map, which was made before the second century A.D., the group of islands now known as the Philippines was called Tawalisi.
Ptolemy's source was apparently a sailor called Hippalus, but there is no reference in the Wiki article to him venturing beyond the Indian ocean. Also, the Wiki article on Tawalisi says we can only guess at the location of this kingdom.
Finally, according to this Wiki page, Ptolemy referred to another Philippine island, Mindoro ('Island of Gold'), as 'Chryse' but there is no further information. Also, looking at Ptolemy's map hasn't helped (maybe because I'm hopeless at deciphering the text).
None of these references, though, are evidence of Greek (or Roman) traders having actually visited any of the Philippine islands. The only source which says this is History of Panay, the credibility of which seems to be in some doubt. However, the reference 21 AD is quite specific...
Is there any evidence to support the reference to Greek (or Roman) traders having visited any of the Philippine islands during the 1st (or even the 2nd) century AD?