In my experience, the cheap prices of Air Asia and other carriers rarely make it worthwhile to use frequent flyer points for interasian flights.

There can be some exceptions, but in general you end up using a lot of points to buy tickets you can pay very little cash for.

There are cheap flights from Hong Kong or Macau to Bangkok, cheap flights from Bangkok to almost anywhere (including Phuket) etc.

It's just not a good use of miles for those tickets. You can end up using 20,000 or more points to fly from Bangkok to Singapore, a round trip flight you can book on Air Asia for about $100.