Don't rely on just one approach to marketing to your customers!
When creating a mobile site, remember to keep your existing marketing in place. If you use email to contact customers, keep using email. If you have a Facebook page, keep your Facebook page current. Using text messages? Ok, you get the point.
Consumers buy from you through many different paths. Some people read email on a PC, yet go to the mobile site to make a purchase. Some get SMS text messages on a mobile, yet go to the PC to make the purchase.
Many will call you. Those nearby will stop in. Do not focus on just one marketing approach. You do need to explore all the ways customers can find you and make yourself available to them. Limiting yourself to one method is limiting your sales.
You are not just selling wine. You are selling convenience and choice. You are also providing information. This is how you will keep your customers and keep them buying.