Re: G**** Vine Trellis
You can set the posts any way you want. Drive by any vineyard and you've got peeler posts (the round green ones ) set in dirt with wire between them. The key here is that they also install an anchor post at either end of the run and run the wires past the last post and down to the anchor. You could use steel posts, either a driven in "T" post or a concrete set Postmaster. Steel would be permanent, and I'd still recommend the anchor at the end. As far as span between posts, probably no more than 10' to 12', keeping in mind that as the plants grow and fruit out, they will become quite heavy and need additional support.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!