I am about to book the RTW through Qantas multi-flight website. I got 640K point to book for two people. My question is, can I book part of the itinerary and then book the rest a few weeks later through the site? How would they calculate my point if I book separately?
You can certainly book the itinerary now and then add or remove segments as long as it still satisfies the requirements and limits of the Oneworld RTW rules. However, each time you modify the booking (ie removing, changing or adding flights), you will be charged 5000 points as a change fee.