Combine the tomatoes, broth, wine, garlic, onion, thyme, basil, cilantro, celery salt, salt, pepper, red pepper flakes and a pinch of cayenne pepper into the slow cooker. Cover and cook on high for 3 hours or on low for 6 hours.
Meanwhile, place the cut potatoes into a medium saucepan. Add cold water to the pan until the potatoes are covered by at least an inch. Add a half teaspoon of salt to the water. Turn the heat on to high, and bring the water to a boil. Reduce the heat to low to maintain a simmer, and cover. Cook for 10 to 15 minutes, or until you can easily poke through them with a fork. Drain and set aside.
Prepare the seafood: cut the fish into bite-size pieces, and peel and devein the shrimp. Season the fish and shrimp with salt and pepper. Set aside in the fridge.
After 3 or 6 hours, add the potatoes, fish and shrimp into the slow cooker. Cover and cook on high for 30 minutes or until the seafood is cooked.