Another data point. I just booked LHR - HKG - NAN return on BA and FJ metal for this Oct/Nov. I booked it all on a BA ticket, 1 PNR. I could only book it on the phone, phone booking fee waived because the flights were not available online. On the BA website I could choose seats on the BA but not on the FJ sectors. On the FJ website my PNR worked and I went into MMB and was able to choose seats. The FJ website shows the Oneworld symbol.

No TPs or Avios awarded for the FJ sectors Interestingly two points raised during the call to book the flights:

1. The FJ flights have BA codeshare flight numbers, for example FJ 392 is BA 8024... booking with the BA codeshare flight numbers increased the price by a lot!
2. When I asked about TPs and Avios the agent said they would not apply to the FJ sectors (I didn't ask what would have happened had I booked with the BA codeshare numbers) BUT he did say that TPs and Avios may be retrospectively assigned once full integration is achieved.... so who knows!?!