Usually Martial Art part gets into play later on. I too have found only a teacher in my town and doesn't teach any Martial Art, he barely tells us a single application per move and not even very detailed.
But the form is the same and learning the form and how to breathe correctly is the first step, so if you don't find anything else do not ignore that possibility.
Chances are that the instructor in the school you mentioned knows nothing about the Martial Art part just like my teacher. But, you might have the chance to get to know where the instructor of that school learnt Tai Chi at and there find a complete Master, as it happened for me.
The Master of my teacher teaches Yang style, Chen style and knows pretty well TKD and Kendo (her faster was a Master of it). Now after learning well what the teacher has to teach me (8-28-48 form) I will try to go to her (as in the Master) and have her teach me the Martial Art part of it (she already showed me once the very basic of push hands).