For those who were wondering, the <wiki/> tag works. The default action is a link to the original wiki at c2.com. So, writing <wiki>RecentChanges</wiki> gives us RecentChanges. If you provide a valid intermap prefix, you make an InterWiki link. So, writing <wiki>MeatBall:RecentChanges</wiki> gives us MeatBall:RecentChanges. However, the intermap isn't very large, so don't get your hopes up that your favourite wiki is listed.
Frankly, I think it's simpler and cleaner to just use the <a/> tag.