TG has a flight out of Manila to either ICN or NRT, {EDIT: Its KIX (Oskaka), my memory was off on both of them.}. The flight down to SIN or BKK is really far out of the way unless you want the extra miles. If you want to pay for your own ticket then Cebu Pacific has really cheap flights out of HKG, PVG, or TPE.

You could buy a PR ticket out of HKG through a local agency at a discount, but its still quite a bit higher than a Cebu Pacific flight. Cebu Pacific is all coach, while PR offers business class too but neither of them particularly shine on the big stage so I'd be tempted to take the cheapest one unless you collect PR miles. (They have no airline partners)