Just to be clear, venting into a roof space is probably illegal. Renovating a bathroom requires by-law approval if the floor has been re-tiled. Your strata committee is being very slow to act on this and if I was an owner and found out this had been allowed to slide, I would be taking the SC to NCAT for failure to fulfill its responsibilities, becasue this is going to cost the owners a lot of money to fix – something over which you will have little choice – if you don’t fix it now.
Get something on the AGM agenda to let prospective buyers know the apartment is non-compliant, if nothing else, that will get the cowboy owner to reconsider their decision not to seek by-laws.