your data will go through the sim card, so I don't see why it wouldn't work. if you know which bands of gsm they use in the phillipines, you can compare it to the phones to make sure your band is supported. I'll try to find it for you.
looks like sun cellular uses gsm band 1800, according to the specs on the sprint tp2, it is a supported gsm band.
my phone (sprint), does show support for band 1800 in the settings, so a cdma us tp2 should work with proper sim card (sprint, verizon, us cellular).
http://www.phonescoop.com/phones/phone.php?p=2185