After consultation with CASA
Captain's sector - F/O and however many S/Os there may be all log the entire flight, chock to chock, whether they were in the bunk or not, as co-pilot time.
F/Os sector - Capt obviously still logs Command, F/O ICUS and S/Os (if carried) co-pilot.
S/Os are limited to logging co-pilot by the nature of their instrument rating and endorsement.
As for instrument time, provided the total time logged is less than the total time spent in IMC, I think everyone can get away with logging a bit. The CAOs allow for logging inflight I/f while manipulating the flight path of the aeroplane through the autopilot btw.