About three years ago, i chip budded 10 Swenson's Reds to wild grape vines in my orchard. All ten took.But, I later killed 9 of them with different experiments. One bud survived my experimenting and prospered
The Swenson's Red chip graft, fruited in it's third year, with about two pounds of grapes.
I used dormant scions and chip budded around the first of June
This appears to be an excellent way to take advantage of wild grapes that may be growing in your area. Plus, it gives a large heavy bearing vine in it's fourth year.
I also planted a Neptune and a Jupiter vine the same year I did the chip budding. Those two plants are barely three feet. While the Swenson's Red is now a very large vine.
That chip graft has now put on about thirty feet of growth.
Hope that helps.
Bob, zone 5 Connecticut.