When you view the tags, any synonyms don't have a wiki:
Edit: It is the same on other sites.
Is this to make it easier to distinguish between them?
To me I (I've just started editing tag wikis on Ask Ubuntu) I then click on it to edit it to create a wiki, and it redirects me to the main tag-wiki-editing page.
(As a side point it doesn't have the number, but I think that that has already been answered here, and not having the number does help distinguish it as a synonym.)
If this is to distinguish tag synonyms, and the wiki isn't wanted there, could it instead look something like this, where the fact that it is a synonym is clearly displayed: