Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 7 minutes. Drain bacon slices on paper towels. Crumble when cool enough to handle.
Combine ground beef with jalapeños, garlic powder, salt, crumbled bacon, and 3/4 cup shredded cheese in a bowl. Spread beef mixture to the edges of each tortilla; set aside.
Preheat a griddle to medium-high heat. Meanwhile, mix cream cheese with sour cream, lime juice, and salt and set aside.
Place tacos meat-side down on hot griddle. Cook, undisturbed, until golden brown and slightly crisp, about 3 minutes. Flip and cook until lightly toasted, 30 seconds to 1 minute more. Fold tacos in half and top with sour cream mixture, remaining cheese, cilantro, and shredded lettuce.
