Under the present CASA rules only the pilot manipulating controls is allowed to log Instrument Flight Time. The instructor may only log Instrument Flight time if they are actually flying the aircraft, if the student is flying regardless of actual IMC or simulated the instructor can not log it.
CASA only has two definitions for logging of Instrument time and that is Instrument Flight and Instrument Ground time, refer to their web site. Simulated IMC (hood or blinds) is still logged as Instrument Flight time.