Havent got it with me to confirm, but Im sure it states in my NZ CAA logbook that centreline thrust hours are not to be logged in the "multi" column. This might not apply in OZ.
I cant find anything in the rules about the logging of flight time itself, but for IFR currency requirements it is made very clear that for currency in "non-centreline thrust" multi IFR, time/approaches in centreline thrust aircraft are not acceptable.