In a small bowl combine the rub ingredients. Season the tenderloins evenly with the rub, pressing the spices into the meat. Cut six 12-inch pieces of butcher’s twine, three for each tenderloin. Wrap the tenderloin with the slices of pancetta and secure the pancetta with the twine. (The tenderloins do not need to be completely covered.) Allow the tenderloins to stand at room temperature for 15 to 30 minutes before grilling.
Prepare the grill for indirect cooking over medium heat (350° to 450°F).
Brush the cooking grates clean. Grill the tenderloins over indirect medium heat, with the lid closed as much as possible, until the meat is barely pink in the center and the internal temperature reaches 155ºF, 25 to 30 minutes, turning once. Move the tenderloins over direct medium heat for the last 3 minutes if you want to crisp the pancetta. Remove from the grill and let rest for 3 to 5 minutes. Cut the tenderloins in thin slices on the bias and serve warm.