PPT is definitely within SWP as far as oneworld is concerned (or it was in 2002). I ticketed ...IPC-PPT//CNS-... as part of a LONE5. Since transpacific surface segments are not allowed, the PPT-CNS segment was considered within SWP.

Our cheap way of getting from PPT to Australia involved taking advantage of the tremendously good value Star Alliance Oceania-Australasia award - 20k miles for a r/t in economy, 40k in biz, on Air NZ. We flew PPT-AKL-CHCx-CNS, and threw away the return portion. The only downside was that award availability is limited, so although we managed to book reasonable dates 6 months out, we were unable to change neared the time.

to the OP - French Polynesia is *very* expensive. If you're backpacking (as we were), there may be better places (= better-value) to chill on a beach.