A mindmap offers a visual representation of a tree/graph of text items. It makes it easy to change the point of view (move around, fold/unfold). A wiki offers a page-based view of hyperlinked text. Typically one page of a graph of pages is visible at a time. Publishing and sharing is very easy with a Wiki. Instead of hosting mindmap files on a wiki, it seems interesting to map a mindmap to a bunch of wiki pages.

A wiki page is mostly text, some text is hyperlinked to the wiki, some to the outside and some to nothing. The page also has structure which would be nice to map to structure too. The structure can be styled (H1, H2, bullet list etc.).