As far as I know (others may correct me if I'm wrong), WYN announced the purchase of VI in 2013. Previously, there had been VI resort reservations available in Mazatlan, PV, and a couple in Honolulu by some kind of agreement between the 2 entities.
Wyn did not buy VI. I think you are thinking of Shell. Vacation Internationale is a points based system similar to Worldmark. Before Wyn, WM and VI had an agreement to make some resorts available in each system. For us, that was the Villas de Santa Fe, the Elkhorn in Sun Valley, Mazatlan and Hawaii. When the WM Santa Fe came in, that VI option dropped off. Wyn took that concept and added some of their resorts to the list.
For me, the key point in the announcement is that Nov 2013 date for purchase to gain the early access. So all those Travelshare folks who were told their accounts were the best are now second rate and the non-Travelshare folks are third rate.