Hi, let me bring a very practical answer to your question.
As far as I am concerned, trying to include FQTV "NZ FF No" Airpoint Dollars and FQTS "SQ FF No" $'s for PPS Status in the bookings has failed miserably numerous times in 2013, apparently because of my corporate travel agent (Amex) which seems unable to handle this.
Similarly, don't try to do this at checkin, whether in Changi or abroad, ground staff (SQ or contractors) simply don't know how to do.
You will waste time and it will get on your nerves.
I've started with an empty LH M&M account exactly 6 months ago and yesterday I reached the 100k for SEN. The way it (actually) worked is as follows, 2 solutions that both work for me:
1. call PPS couple of days before the flight, they can arrange the double dip NZ-SQ PPS (and they are more skilled with the system apparently)
OR
2. do the whole KF-PPS thing (miles in your KF account and PPS $ in your PPS account) then after the flight email PPS asking them to transfer the miles only. It works, providing you're not in a rush, maybe 1-2 months to have the miles landing in your NZ account.
If solution 1 failed you still have #2.
As far as retroactive claims for past flights, yes you can (sound familiar
, at least on M&M, you can claim up to 6 months back but you have to provide the BP by snail mail (because it's a SQ BP).