As you probably already know, Vistage does most of its actual client-facing work through 1099 consultants, usually experienced business executives, who "chair" groups of CEOs or small business executives in their home cities.
I was recruited by Vistage and went through the process. It starts with several interviews with recruiter(s), followed by a WebEx with a regional Vistage exec or execs, followed by an invitation to their San Diego training event. At the end of the event (which I paid to attend, along with all my T&E), I was told that they decided they already had enough people to support the city in question.
I enjoyed the experience of talking with them, received very positive ongoing feedback and was quite surprised that the fact that they didn't need people in this position didn't come up until the end of the process which took several months of my time and Vistage's.
My other comment is that it is an enormously time-consuming process for both the candidate and I assume for Vistage given that these are 1099 roles. I've successfully applied for actual employment with much higher earnings potential and actual benefits with significantly less effort.