Bring a large pot of water to boil. Season with salt, pepper and bay leaf.
Add lobsters to pot and cook 5 minutes. Remove from pot and allow lobsters to cool. Reserve cooking water for sauce. Remove meat from tail and claws. Chop in 2-inch pieces and set aside.
Heat half of the olive oil in a skillet. Add garlic clove and lobster shells. Sauté until garlic is golden. Add flour and cook for one minute.
Add wine to skillet and cook until reduced by half. Season with salt and pepper.
Add enough cooking water to cover shells. Simmer until reduced by half.
Heat remaining olive oil in another skillet. Add onions and sauté over medium heat until soft.
Add cherry tomatoes and the wine sauce.
Cook spaghetti half of the recommended package cooking time. Drain and add pasta and lobster meat to sauce.
Simmer 6 more minutes until pasta is al dente. If needed, add more lobster cooking water.
Season with parsley and butter and serve.