What are the fatigue regulations in the US and Australia for military transport helicopters/rotorcraft?
The US Federal Aviation Administration does not regulate aircraft owned and operated by the military services. I suspect that is the same situation with Australia's CASA. 

Parameters for aircraft service life for military aircraft are defined by the manufacturer. The aircraft is designed to meet the requirements specified by the agency requiring the aircraft. This is usually expressed in flight hours, cycles or a combination of that and possibly other parameters.