Place the towel in a small bowl and pour the wine over it, allowing it to soak for 20-30 minutes. You may need to stir it around a bit.
Preheat the charcoal grill for high heat, removing the grates. We will be cooking directly in the coals. Lump charcoal or briquettes will work best.
Squeeze out the excess wine from the towel gently, and place the towel on a large cutting board. Open it up into a diamond shape so a corner faces you. Pour out the salt across the towel into a thick layer, going from the left to the right side. Sprinkle the spices all over the salt.
Prepare the beef when you’re ready to grill, not ahead of time. Roll the beef tenderloin in the spices, and place it in the middle of the salt. The tenderloin should sit parallel to your shoulders, with a corner of the towel pointing to you. Roll the cloth and salt, starting from the far end of the cloth, creating a compact roll. Take the points of the cloth at each end of the cylinder and tie them together on the top of the towel. Use butchers twine as needed if your towel is not able to be tied.
Rake the charcoal into an even layer at the bottom of the grill. Lay the wrapped tenderloin directly onto the coals with the knot side up. Do not disturb it for exactly 9 minutes. Carefully flip it, cooking for another 9 minutes - or until you are within 5 degrees of desired temperature. The cloth will likely burn up, this is typical.
Transfer the salted beef to a metal platter or baking sheet and allow it to rest for 2 minutes. Using the back of a chefs knife, hit the salt crust to crack it open. Remove the tenderloin and brush off excess salt, slicing it on a cutting board immediately.