Sorry, that is not a official function. Also I don't understand what you actually want to do. Do you want to check for the parent album? there is a function and there is also one for the "uralbum" to get the toplevel album of any of its subalbums. See the documentation, I don't have the links at hand.
Just to note: Nice site and usage of Zenphoto in general, that is the type of usage I/we actually had in mind when making the Zenpage plugin. Be sure to submit that to the showcase when it is ready..;-)
Btw, you might want to consider to update to the stable 1.2.8 release as you are using the RC1.