Hi Matt,
Thank you for using our services.
In Sitefinity 3.7 SP1 we have changed the Wiki module to be a Generic Content based module so have the data provider listed under the Generic Content providers section in the web.config. Then in the wiki section in the web.config you have to define which generic content provider you have to use. Here are the changes in Wiki from 3.7:
However this does not change he fact that the Wikis are stored in the XML Data file.
All the best,
Radoslav Georgiev
the Telerik team