Searches from a smartphone in Google now include a "Mobile Site" in front of every results. By including this tag Google is puting the litght on site which are mobile friendly. But there is also a change in the algorithm on the way, sites that are not defined as mobile friendly will be dropped down in the search engine results list. While no evidence of dropped site has been reported yet, it is pretty much guaranteed it will happen.
You don't have to re do your web site from scratch if it is not mobile yet. You can consider just changing the theme of it and make it “responsive.” This means that you can have one website which automatically reformats for the device being used to view it. You can also go for a dedicated mobile websites. Google will like both.
Vizyshop can help you audit your mobile website and mobile strategy. Feel free to contact us.