Combine the water, white wine, lemon juice, onion, celery, garlic, peppercorns, thyme, and bay leaf in a 3-quart saucier and bring to a boil over high heat. Reduce the heat and simmer for 8 minutes.
Add the bass fillets to the court bouillon, partially submerging them in the liquid. Cover the pan with the lid and poach the fish for 5 to 7 minutes. Be sure not to overcook the bass. Remove the bass from the poaching liquid and season with salt to taste.