Now I am a little confused. Do you want to go to Singapore or do you want to go to Indonesia? If you are doing both, note that flights from Singapore to Bali (for example) can be cheap. I booked business class on KLM's flight (one way) for US$3xx. Coach is probably like $150.

Getting the AAdvantage card isn't going to get you on SQ. But AA does have 1 way awards, so you could use those points to book CX F from SFO to SIN via HKG. The nice thing about AA is that they don't charge a lot of taxes or fees.

While UA did devalue their chart, it looks like it's not terrible when I just did a quick search of their awards (40K one way in Y, 80K one way in F).

Keep in mind that using 1 way awards can be quite useful if are doing an open jaw (arriving in SIN, staying there a few days, and then returning from Indonesia).