As above - it really doesn't matter for AUK.
A club is just a collection of like-minded people, so you can form your own club and ask the Membership Sec to add it to the list.
We've got several new clubs that are just collections of people who like riding their bikes a long way that have rather dominated the club championships over the past few years and that's all great, but some people get a little worked up over what is a 'real' club and what isn't.