Looking at companions for grapes.

I am looking for companion plantings for grapes. I know that everyone says that grapes are overly sensitive to competition, but nature doesn't work that way. In my experience foraging, I see wild grape in the ditches often near asparagus.
Does anyone have any other experiences/observations to share?
Does anyone know in what environment grapes grow in their areas? I don't need river grape suggestions as this is not a landscape I can dulicate.
I know that quite a few types came from Italy. Maybe someone have observations from that region. France has been cultivating them for so long, I don't know that there would be much to glean from that area. Maybe I am mistaken?/!
Let me know, I am all ears!
Thanks.  

Look at it this way:  grapes have a small footprint but a large overhead, That is they are competitors for light.  With a permaculture design this can be a solution.  With an East/West trellis they can provide summer shade for a structure or plants while still allowing sun to plants under them unless one is close to the equator.  In my homestead setting I train them up a post to 6 or 8 feet high then out on a wire for 10 to 20 feet in each direction.  All that space under them is free for other planting whatever matches the growing conditions and your needs.

Note I am doing over a 4 foot fence to keep the deer out. The do the necessary pruning of the vines and don't jump over.