I understand member organizations as any organization that can become a member of WGI. I do not see a significant difference with the name organizational member. WGI representative organizations around the world are very important to leading the world with CT and should have a name that is consistent with that. In that light, I prefer affiliate, branch, representative, etc.
In addition, I think we will be setting up open competition to current organizations because other organizations can become member organizations on the same region or country. That is not good for the relationship.