I've used it for rabbits on just such a waterer for many years and didn't see any ill effects. But then, I didn't look up into the nipple to see if there was any corrosion going on, but my rabbits didn't suffer any.
Could be stainless steel is impervious to acetic acid. I know that galvanized tin is not...I got to see the corrosion first hand on one of those waterers after just a small time with ACV in the water.