I was pretty sure Thal was going to write some version checking code to allow for this.
I had a similar experience a couple of months ago with the wonders not being available unless you had the FULL DLC content.
I think it was with the Halicarnassus but I just can't quite recall.
EDIT:
Just went back through my communication logs, the problem I experienced, and is similar to what is described here, can, according to Thal, be eliminated by moving our code to SQL that includes an error-checking clause like WHERE.
Do a check for the existence of that building in the database and depending on the outcome, branch our code as needed.