I am pretty leary, myself, about attaching anything to the wall in my RV. First, most RV walls are questionable whether they are designed to support much weight attached to them. And second, unless you know the construction details, you never know what might be behind the wall - like electric wires, water lines, etc. - not things that you'd want to accidentally drill into.
That being said, I had an Airstream several years ago and I had the factory service guys attach an Omni cantilever wall mount for a small flat screen TV. I would think that something like that would be the ideal thing to use, if you were intent on having a wall mount. Personally, I'd just use a few books under my vise on the desk, if needed.