Many thanks (JimmyT) for your reply. I think the owners will definitely vote against the by-law that we are proposing for the next AGM, however it is interesting that you say that if they vote against it then it would be an interesting case to take to NCAT because that is what I was thinking of doing.
From what I have read it seems we would have to go through mediation before we could take it to the tribunal but as the owner of the AirBnb only seems to be interested in pursuing their own interests, I would be surprised if mediation succeeded.
Thank you, your reply has been helpful in that I am thinking in the right direction!