I am also generally in favour of dogs!
It is not enough to claim your dog is an assistance dog for a health issue. The dog must be trained and officially qualified, and this takes considerable time and effort, but results in extra nice dogs.
Although the landlord may have given permission to keep the dog, a dispute at NCAT with the other owners may not be palatable to the landlord, even if you are prepared to go that far.
Your relationship with your dog will hopefully be for many years to come, and the question of permissions to keep the dog with you will keep recurring whilst you are either a tenant or living in a strata scheme. A longer term plan needs to be thought about, and avoiding NCAT also?