Vineform is for the early EM gamers first and foremost. Grabbing a couple while you've only got a few hero levels on you is silly useful. Afterwards, it's still a decent late-game investment if a boon or two takes you out of 1hit-KO territory.
EM is definitely more caster than melee, but her aim is to support spellswords (a build choice which we're trying to make more appealing outside Sorcerer).