Ive never used it, and dont eved do AG batches, but I would think it would be alright if you use at RV grade water hose. These are made up of a different material than normal garden hoses. I use one for my camper and you cant taste the hose like you can sometimes from a regular hose.
I don't see any problem with using the hose. I think people worry way too much about water when making beer. After all, historically one of the reasons people made beer was to make their undrinkable water drinkable.
A long time ago, before I ever dreamed of making my own beer, I remember someone asked a question during the Miller Brewery tour about the water and the tour guide said they just use Milwaukee water right out of the tap. He claimed, at least, that they didn't really do anything at all to it except to make beer out of it.