I'm looking for a Dr in Australia or Philippines that does sculptra for the buttocks?

Far more important than the technique is the skill and experience of your plastic surgeon. Choose your surgeon rather than the technique and let them explain why one technique may be better than another.  See the below link on some suggestions on finding the most qualified Plastic Surgeon for you.  Always insist on a board certified plastic surgeon.

This area needs numerous vials of Sculptra over time to build volume, and in some instances the results are subtle and will need to be combined with fat or implants to achieve desired results. Don't let distance dissuade you. I recommend seeing a body shaping expert for a formal evaluation.  Best, Dr. Emer.