1. Mix the seasoning ingredients with the wine, and keep aside. Then, bring the roast to room temperature, and place it in a freezer bag. Pour the seasoning mix over the roast and seal the bag, then store in the freezer for two to three days. Ensure to turn the meat occasionally every day so all parts are flavored.
2. Preheat the grill to 300F, bring the marinated roast out of the freezer bag, and pat it dry with paper towels. Then, grease the rack with non-stick spray, and set up a two-zone cooking area.
3. Place the seasoned roast on the rack and stick a meat thermometer at its thickest part, then cook until the indicator reads maximum internal doneness of 135F.
4. Remove the roast from heat and cover in foil, then let it sit for 30 minutes before slicing.

You can also watch this video for more help.