Mix 1/4 cup each of the wine and oil, 2 teaspoons of the thyme, Worcestershire sauce, 1 teaspoon of the sea salt and garlic powder in small bowl. Place steak in large resealable plastic bag or glass dish. Add marinade; turn to coat well. Refrigerate 30 minutes or longer for extra flavor.
Meanwhile, heat remaining 1 tablespoon oil in large skillet on medium heat. Add shallots; cook and stir 3 minutes. Add mushrooms; cook and stir 3 minutes. Add remaining 1/4 cup wine, vinegar, remaining 1 teaspoon thyme, pepper and remaining 1/4 teaspoon sea salt. Simmer 10 minutes or until sauce is slightly thickened and mushrooms are tender. Set aside to keep warm.
Remove steak from marinade. Discard any remaining marinade. Grill over medium heat 6 to 8 minutes per side or until steak is desired doneness. Serve each portion of steak with about 1/3 cup mushrooms in red wine sauce.