2.4 GHz radio Systems - If a club member personally imports a transmitter and that transmitter has FCC or CE (or both) certification by the manufacturer, can that transmitter be used in Australia without a C Tick?

The C Tick is a requirement of the ACMA for product that is sold in Australia as providing evidence that the supplier accepts the responsibility that the product meets the Australian Standards. The suppliers are subject to audit by the ACMA to prove they have the supporting documentation.

Certain specific FCC and ETSI Standards, which are listed in MOP058, are accepted by the ACMA as being the equivalent to the standards specified for operation under the 2.4 GHz Class License.
If a C tick has not been applied by either the manufacturer or the importer then the user is the one who accepts responsibility for the product meeting the Australian Standards. This is the legal situation not an MAAA position.