Melt butter in a large Dutch oven over medium-high heat. Add celery and onion; sauté 5 minutes. Add mushrooms, rosemary, and garlic; sauté 5 minutes. Add broth and wine; bring to a boil. Reduce heat, and simmer, uncovered, 10 minutes.
Lightly spoon flour into a dry measuring cup; level with a knife. Place flour in a small bowl. Gradually add milk, stirring well with a whisk; add to soup. Bring to a boil. Reduce heat, and simmer, uncovered, 8 minutes.
Add turkey and remaining ingredients; cook until heated.