The CSM yu spoke to was wrong....has nothing to do with the EBA and never has.... its Qantas Policy and in fact the position of the crew is actually strengthened
CCOM states clearly that Cabin crew determine who get the seats. It must be unanimous of all Operating Crew. If one crew member (cabin) says no then no one can use the rest seats.
The role of the Captain is firstly to be advised that the Cabin Crew have offered the seats... The captain will then determine whether that fits with the weight and balance and fuel requirements. If the captain determines that by offering the seats there are no implacations for the Aircraft then he/she will advise ground staff that the use of the seats is authorised.
It is the CSM that will then advise which passengers ( by name) who will be allowed to use the seats. If the passengers are subsequently offered a passenger seat and the crew seats are not required by them, the ground staff "may" approach the CSM to see if the seats are available for anyone else and that will then be either authorised or denied by the CSM.
That is what is contained in Qantas Policy as negotiated by the FAAA in the CCOM.....
The seats are at ALL times under the control of the operating cabin crew who are the only ones that can determine who may use them. The captain as the PIC has the ultimate say in whether they may be used or not but NOT who can use them.