Hmm, gorgonians are said to have anti-microbial properties in their mucous, so that could be beneficial for dwarfs. The gorgonian will also help eat some of the food you put in the tank. Which dwarf species are you getting? I assume the only legal one... Anyways, from what I read, you don't want anything larger than a 10g tank, preferably smaller. I'm sure they'd enjoy having lots of macroalgae, though. Maybe halimeda and maidens hair. Some seagrass as well. Not sure if Caulerpa would be too big for them to grasp. You have to feed dwarfs a ton of food everyday, so I wonder if it might be beneficial to have some filterfeeders in there as well, such as porcelain crabs?
As for the gorgonians being irritated by the dwarf seahorses, I'm not sure if they'd be all that irritated by them. They're so tiny, that if anything, they might just close up polyps in the immediate vicinity of where they're being grasped. They'd probably react the same way as they do when a bristleworm or brittlestar is crawling around on them. Plus, corals do get used to being poked and prodded at after repeated exposure. You could try gently nudging your gorgonian in various spots throughout the day to get it used to being touched before trying it out in the dwarf tank.
