The Mexican Cafe is probably the best tequila bar you will find in Auckland, possibly New Zealand. They have around 80 or so tequilas, and I find that they do get new ones in periodically. Most places here have 1800 as their top shelf, so to see such a selection here is quite impressive.
The bar staff have a good general knowledge and there are a couple guys who take the time to taste stuff so they know what they're talking about. But I'm not sure I would say everyone does. They are pretty good guys though and the mixed cocktails are great. Stop by for Happy Hour and good drinks.
The food is a little yet to be desired. It's decent at best. It has been inconsistent for us. Some days are better than others. But for someone from Southern California, it's not quite up to par. The prices aren't too bad for here in New Zealand. And it is worth noting that they do not tac on the typical surcharge (usually around 15%) that everyone else does on statutory holidays.
The ambiance is pretty cool though, old style los muertos skeletons, mexican/latin music playing, and if you come on a weekend night live DJs are pumping up the place as some tables are cleared for salsa dancing. It's usually pretty busy for lunch, happy hour and dinner, despite having ok food, the drinks must pull people in. Though any good Mexican food here is hard to come by.
By far, if you're looking for a tequila bar down under, come check this place out. They have a location in Christchurch that I understand has a different selection, but I have yet to go there.