It is best advised to buy only wines that have a VQA neck seal (Vintner's Quality Alliance). These wines are not only strictly controlled in respect of their guaranteed origin but are also quality tested for taste, colour, bouquet etc.
This gives assurance that you have bought one of the better Canadian wines. Canada also has two levels of guarantee of origin: the broad Provincial Designation Wines category i.e. British Columbia or Ontario, and the more precise Viticultural Areas Wines which originate from one of the recognised wine districts su'ch as Okanagan Valley, Similkameen Valley, Fraser Valley, or Vancouver Island for British Columbia, and Niagara Peninsula, Lake Erie North Shore, or Pelee Island for Ontario.