Like everyone else, I'm using my smartphone all the time when looking up stores and restaurants. But it is obvious that often their web design is optimized for 27" screens and superfast broadband rather than 4" and a crappy Edge connection.
If your visitors are going to check opening hours, menus or make a reservation for a local service on your web site, design for mobile first.
That means menus that are friendly to fat fingers, a design that works on a normal iPhone's or Android's screen resolution and a design that loads quickly.
Both your customers and sales director will be much happier if you go mobile web first.