i was surprised to see that wikipedia has added one of my site , but it added as http://site.com instead on www.site.com , will the link there be of any help?
It will help but you should probably have a 301 redirect from http://site.com to www.site.com avoid link canonicalization and duplicate content issues. If you can't do that, you can try using the new Preferred domain feature in Google Sitemaps. That may take care of the problem from Google's perspective.
Or just change the link on Wiki. Most likely if you make the comment no one will mess with your link. Just put in the comments that someone else linked to your site but you would prefer a link from www. link.com rather then link. com Any more editor will understand and allow it.