Just as a caveat to this thread, I travel the region almost every year for vacation and do not find great value in some of the routes you are talking about taking as airfare around SE asia is usually so cheap. I'd just pony up the cash for my short hops in SE Asia and earn miles there and use my points on Longhaul SQ to SE asia.
That being said, I searched one date and immediately found a seat BKK to VTE
