Go to bettysplenden.com and read the genetic study.
Theoretically (IME not 100% true)
Long fins are dominant over short fin (IME: depends who's genetic back ground is stronger).
VT is dominant over other types. TRUE. but you will also get a mix between VT and what ever it was crossed to.
By "wild type" do you mean one of the wild bettas or the traditional short finned fighter? You'd probably get mostly VT, some with wider spread. If you're lucky, you might get one or two round tails. A few short tails and some "in between tails"
Yes, today's modern fin types came from traditional forms. But to get the mutating genes may take a life time of breeding. I'd suggest you breed the types you like and make life easier.