What's with the criteria and params lists?  You know what the query needs to be - there's no need to build it via a StringBuilder.  Should just be like this:

    client.buildQuery("/s-ramp/ext/DtgovEmailTemplate[@template = ? and @template-type = ?]").
        .parameter(template)
        .parameter(templateType)

In fact, I suggest removing the createQuery() method entirely and just inlining the above code wherever this method is being called.