Growing Grape Vines in the Caribbean region
You submitted 3 almost identical questions so I killed the other two.
You can transplant anytime you want, I doubt the vines will go dormant in that climate. Yes you can use a large pot for the first year I would suggest a several gallon pot since grapes grow fast producing a lot of foliage and need a lot of water.
As for soil I would avoid too much sand (too droughthy) or too much clay (might be too wet). A loamy soil with about equal parts of sand, silt and clay. You should think of transplanting into a permanent situation or moving to a really big pot before they become root bound.