Heat 2 tablespoons of the oil in a medium skillet over medium heat. Add onion, cook, stirring frequently about 5 minutes, until translucent. Add garlic. Cook, stirring, 1 minute; let cool.
In a large bowl combine breadcrumbs, milk, egg, cilantro, salt, pepper and allspice. Add bison and onion mixture. Mix until blended. Roll into 1 1/4 inch balls.
In a large non-stick skillet over medium heat, drizzle 2 tablespoons of oil. Brown meatballs in batches, transferring to a large baking pan. Cover with foil to keep warm.
To serve, drizzle meatballs with sauce.
To Make the Sauce
In a medium saucepan over medium heat, combine tea, dried blueberries, sugar, anise and salt; bring to a simmer and simmer gently for 5 minutes.
Stir in frozen blueberries; increase heat to medium-high, bring to a boil.
Let boil for 3 minutes. Stir in vinegar. Remove heat and set aside.