The water system is common property up to the point where the pipes emerge from the wall.
Water hammer is most often a problem with the system, not the taps. The taps may trigger the problem but they are not usually the cause.
The Owners Corp is required by law to maintain and repair common property. With that in mind, it is the OC that you should be thinking of taking to NCAT, not individual owners.
Not all plumbers will be able to identify and cure the problem – you (or more accurately, the OC) need to hire someone who understands the issue in apartment blocks and knows how to fix it. Google “water hammer fix” to see who’s around.
As stated before, this is most likely a common property issue and if the strata manager is reluctant to pursue it on the scheme’s behalf, you have to ask why you are paying them their fees.
Have a look at this page (not necessarily an endorsement of the company listed here – just a good explanation)