This is the way I was taught to do it:
Taxi Call: "Bankstown Ground, ABC Cessna, Received Charlie, Taxiing VFR for 'Destination' via 'departure point', runway 11L."
Run-up Bay: "ABC Request Airways Clearance"
I think you do actually have to request the clearance..although after the Taxi call they may just issue you with the clearance anyway as they know that's ultimately what you want.