My understanding is the following:

Wilson had no statements, either before or in the first few days after the incident, where he complained about the ability of illegal aliens to buy into the public option (though they couldn't, of course, use government subsidies to do so). Instead he, like, to the best of my knowledge, a large majority of the Republican caucus, was worried that there was only an unclear and insufficient mechanism (essentially to be added later) to ensure that illegal aliens didn't use government money for healthcare.

Along with that, my understanding is that the complaints about illegals being able to purchase into the public option, even without using federal funds, only arose after the fact to try to justify Wilson's remarks.

Were illegal aliens unable to purchase health insurance (using their own, and not federal money), I would actually be a little disappointed. It seems an unnecessary restriction of the free market. Additionally, and unfortunately I couldn't find a link on the first page of google, I thought I read that allowing illegal immigrants access to a public option would have the potential to actually decrease costs to American citizens.