Fill a stockpot with 1 to 2 inches of water and set over high heat. Add the sea salt, seafood seasoning, peppercorns, 4 of the garlic cloves and the onions. Once the water is boiling, add the lobsters. Cover the pot and steam the lobsters for 8 minutes (they won't be fully cooked yet). When finished, remove the lobsters and shock in ice water.
Carefully remove the lobster meat from the shells, saving the juices, and coarsely cut into large chunks. Toss with the mayonnaise and about 1 cup of reserved lobster juices (the mixture should have a wet, thin consistency). Reserve.
Melt the butter in a small saucepan over medium heat with the wine and remaining clove of garlic. Reserve and keep warm.
Line a large, flat griddle with foil and heat over medium heat. Arrange the lobster mixture on the foil and cook, stirring occasionally, until heated through, about 5 minutes.
Heat a large, flat grill pan or skillet over medium heat. Open the buns, brush the garlic butter on the insides and toast, buttered-side down, until golden brown, about 1 minute. Evenly divide the warm lobster meat between the rolls, brush the meat with a small amount of garlic butter and garnish with a dash of seafood seasoning.