I had a dating scan and recently a morphology scan and both were bulk billed. Not sure where in Brisbane you are, but you can use your scan referral anywhere, doesn't have to be the place the doctor says.

QScan bulk bill, I used the one at Cleveland, but they have 7 locations in Brisbane. That was for my dating scan.

For my second scan I used Queensland Radiology (I think thats what it is called) in Rochedale and it too was bulk billed.