When I worked in TAA Res in the late 70's the good relationship with Ansett still existed. Res Clerks from both airlines would frequently phone the other carrier when a passenger wanted a flight that was full, or a more conveniently timed flight. It was when providing service was the name of the game.
If memory serves, Macs was the pub situated between the TAA Head Office at 50 Franklin St, and the Ansett Head Office on the corner of Franklin & Swanston. A popular watering hole for staff of both airlines.