I run vx's with no bends, but one of my stock steel 13" rims had a similar bend that made the car pull to one side. aluminum will produce stress fractures sometime later if you attempt to bang it out, so I would just run it and see if you notice it pulling you. As long as you don't see any stress fractures around where the bend is I think it should be safe.
It doesn't look too bad, but it could potentially cause steering wheel vibrations if you run that rim on the front... You can try your luck with a wheel repair place or looking for another VX rim at a local scrap yard...
If it was a steel rim, I'd say straighten it out. With steel you could do it with a sledgehammer and a steel. However, I'm not sure about the aluminum. I'd go with Clencher's suggestion, just leave it alone and try running it on the back. If you don't get some ugly handling issue's, it won't be to much of a risk, their.
Re-consideration. What you could do, I think, is take the wheel off of the rim, use a block of 2 x 4 and a sledge hammer. You can mount it on one of the back rim's and use the a block on the ground to mark the alignment and then bring the bend back into alignment. I'd still run it on the back, after your done, just in case, but I think your going to get wobble and vibration issue's if you just use it as it is.