Whisk together the red wine, garlic, bay leaves, salt, and black pepper together in a large glass or ceramic bowl. Add the sirloin cubes, and toss to evenly coat. Cover the bowl with plastic wrap and marinate in the refrigerator for 8 hours or overnight.
Preheat an outdoor grill for medium-high heat, and lightly oil the grate.
Remove the sirloin from the marinade; shake off excess liquid. Discard the remaining marinade. Skewer the beef onto the prepared skewers.
Cook on the preheated grill until the beef cubes start to become firm and are reddish-pink and juicy in the center, 2 to 4 minutes per side for medium-rare.