Just a heads up found this article:
Navigation Menu Universal ViewerAnd this syntax worked:
<li style="font-weight:bold;"><a href="<%# IfEmpty(Eval("DocumentMenuRedirectUrl"),GetDocumentUrl(),Eval("DocumentMenuRedirectUrl")) %>" <%# IfEmpty(Eval("DocumentMenuJavascript"),""," onclick=\""+Eval("DocumentMenuJavascript")+"\"") %>><%# IfEmpty(Eval("DocumentMenuCaption"),Eval("DocumentName"),Eval("DocumentMenuCaption")) %></a></li>
Not sure why the text/xml syntax wasn't working, but found a solution nonetheless.