Whisk together peach jam, bourbon (if using), garlic, and citrus zest and juice. Slowly whisk in olive oil until incorporated and season with salt and pepper. Taste and adjust seasoning, if desired.
Place pork tenderloin in a large Ziploc bag. Add the peach marinade and zip the bag. Place in the refrigerator and allow to marinade at least 2 hours (or overnight), rotating the bag halfway through.
Preheat grill to medium-high; coat with cooking spray. Place the pork tenderloin on the grill and allow to cook 15-20 minutes, turning halfway through, until internal temperature reaches 140 degrees (the pork will carryover cook). Allow the pork to rest on a cutting board for 5-10 minutes before slicing.
In the meantime, prepare the salsa. Mix together the peaches, jalapeno, red onion, citrus zest and juice and cilantro. Season with salt. Taste and adjust seasoning, if necessary.
Serve sliced pork tenderloin with peach salsa.
Notes
Cooking Tip: The pork can also be roasted in the oven at 375 degrees, until the internal temperature reaches 140 degrees.