The agency will be tasked with drawing in existing and new customers by focusing on services such as the AirMiles credit card scheme, flights, rewards and other passenger services.
AirMiles will join the likes of Saga and National Car Rental on the Tamar roster of travel clients.
AirMiles head of marketing Fred Prego said: “In a competitive marketplace it was important for us to get the most out of our search marketing strategy to help drive traffic online and sign up for credit cards.
The AirMiles service is the longest reward system in the UK and has established partnerships with major consumer brands such as Tesco, Lloyds TSB, Comet, Ebay and Carphone Warehouse.
Tamar client services director Lesley Oliver added: “The travel and rewards sector is becoming increasingly sophisticated in using search, but few brands are striking the right balance between paid and natural search.
“We’re looking forward to working with AirMiles to make the most out of search and achieve its digital marketing goals.”