In medium saucepan, heat oil over medium-high heat and cook onion, stirring occasionally, 5 minutes or until golden.
Add maple syrup, ketchup, bourbon and hot sauce. Bring to boil; reduce heat and simmer 5 minutes or until sauce is reduced by 1/4 cup. Remove from heat.
Whisk in mayonnaise until smooth.
Grill chicken, turning once and brushing frequently with mayonnaise mixture. Cook until chicken is done and juices run clear.