The wordings "subject to individual premises" is to allow indiviual MCST to decide on their own the limit.
I would suggest that TS ask to see the AGM documents to check how the resoluation was worded and how was it passed at the AGM. In some estate that pass such resolutions, they have provision to allow exisiting owner of such dogs to con't to keep these dogs till the dog pass on and there after they have to abide by the ruling.