Preheat oven to 300°.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, 1/2 teaspoon salt, and 1/4 teaspoon black pepper in a large zip-top plastic bag. Add venison; seal and shake to coat. Remove venison from bag; discard remaining flour mixture.
Melt butter in a Dutch oven over medium-high heat. Add venison, onion, and garlic; sauté 5 minutes, browning venison on all sides. Add wine, scraping pan to loosen browned bits. Add 1 teaspoon salt, 1/4 teaspoon black pepper, sugar, and remaining ingredients to pan; bring to a boil.
Cover and bake at 300° for 3 hours or until venison is tender. Remove berries and bay leaf before serving.