Hi antchristie, welcome to the forum

As Englishman said, if your employer is relocating you to Manila then your salary will be (or should be) in line with what it is now depending on any negotiating you can do.

If your thinking of just moving to Manila then finding a job, don't expect western salary level it just won't happen. (You'd be lucky to even find a job based on having permit etc)

To answer your question and just as an example, if you could secure a contact centre job, you could expect to start at P10k-P12k per month. That's working 12hr shift rotations.
If you could beat off all the competition to reach supervisor or manager level within say
2-3 years you could expect P18k-Pk30 again on 12 hr shift rotations.

This is based on a family member's info working contact centres in Marikina 2008-2010

Staff turnover is extremely high and conditions very stressful. My family member already quit and returned to Hotel management in Davao.

I don't even think he managed to save anything from his time in Manila