Forum Moderators: Robert Charlton & goodroi
Images first need to be uploaded to the Wikipedia namespace, and the file named according to their policy conventions, right? So the copy of the image that is on your site would not be more likely to appear in Image Search, if that's what you're asking.
A Google Image Search on [site:wikipedia.org] returns about 10,000 results, and [site:en.wikipedia.org] returns about 4,000. That doesn't sound very preferential to me.