Show-Stopping Oyster Pot Pie

8 slices thick-cut bacon, chopped2 c. chopped Vidalia onions½ c. chopped celery1 red bell pepper, seeded and diced2 T. minced garlic1 ½ c. plus 6 T. flour, divided1 qt. raw oysters, drained but save the juice2 c. heavy whipping cream¼…