Foster scored in the 2-1 win in the final against Lesotho in Zambia on Saturday to end the youth tournament with three goals.
The 17-year-old, who recently had a trial with French giants AS Monaco, has provided one assist in four league appearances for Bucs since his promotion to the first team this season.
Foster told his club's website: "It's always good to represent your country and to do well, so I'm very proud of the team and my contribution towards that.
"However, the Amajita chapter is now behind me. My immediate focus is to get back to training with my club where I can compete for my place in the team.
"Obviously it won’t be easy as we have a lot of quality players but I am ready for the challenge and looking forward to fight for my place."
The Buccaneers, who have struggled for goals in 2017/18, ended the year with a 2-1 defeat at Free State Stars on Saturday, and currently find themselves in sixth place in the standings midway through the campaign.