To be fair, I didn't actually have the opportunity to eat at Adelante. I visited the restaurant and discovered that it was closed for the holidays. However, I called to ask about vegan options and discovered that the wheat tortillas are not vegan (but the corn tortillas are). In fact, a lot of the items on the menu that looked like they might have been vegan contained hidden dairy products.
The good news is that the staff at Adelante seemed to be pretty well-informed about the ingredients in the food that they serve, which is more than can be said for many Mexican restaurants. It sounded like there are a couple of items that can be made vegan, you just have to ask.
Also, for lacto-ovo vegetarians, there are some enchiladas and tamales without meat products in them (a rare treat, since cheese enchiladas are often cooked in chicken broth and most tamales are made with ground pork).