No, Tinder does not come with an 'extension' package as the one that exists for Smack. Tinder, unlike Smack, does not aim to deliver a full-featured XMPP implementation. Tinder provides more basic 'building blocks'.

In any case, most stanza representations are implemented as a kind of wrappers of dom4j Elements. If you're looking to implement a class that represents an IQ stanza with a specific child element, you can easily extend Tinder yourself. Have a look at the Roster class, for example.