Hi
I might be interested in a club or group. If your starting a club I suggest that you base it on Meet up.
Once started the group would be announced to meet up members localy. In Scotland there are plenty other outdoor groups, there would probably be some interest from these. Members would receive notification of the new group, could be thousands of people contacted.
There is a cost involved in running a group through meet up however it would reach out to people, easier than word of mouth but still would take some effort as you still have to plan and organise regular bike runs.
As far as groups in existence now, there are none at the moment on meetup in the UK, never mind Glasgow based solely on e-bikes. There may be sub groups of regular cycling clubs but they would not be easy to spot.