I don't think the vignetting adds any specific value to this shot. I think the shot has to stand on its own first and this one, while there are some good features in the color and angle of the composition, lacks any real grab factor for me. I get the feeling it is a SOOC (straight out of the camera) shot. You also have a pretty serious dust problem on your sensor. These can be fixed during post processing. I'd be curious to know why you felt the need for the vignette.