The WPP agency beat Havas EHS, TMW and Aimia, which owns the software behind Sainsbury’s Nectar Card loyalty scheme.
Wunderman will work across countries including the UK, Ireland, Denmark, the Netherlands, Sweden, Finland, Norway, Belgium, France and Luxembourg.
Campaign revealed earlier this year that Coca-Cola had issued an RFI to direct marketing shops about the brief.
A Coca-Cola spokeswoman said: "We can confirm we have appointed Wunderman to manage our CRM programme across North-West Europe and the Nordics. We do not provide further comment on [the] pitch process."