Put mint leaves in the punch bowl and press with a muddler to release the oils.
Add rum, pineapple juice, lime juice, and simple syrup to the bowl. Stir well to combine.
Place the mixture in the refrigerator for 1 hour to chill and let flavors blend.
Just before serving, add club soda and pineapple chunks. Stir gently.
Fill glasses with ice and pour in the punch mixture.
Garnish each glass with fresh mint leaves and pineapple wedges.
Notes
Keep the club soda separate until serving time to maintain carbonation. The base mixture can be made up to 24 hours ahead.Fresh pineapple works best, but canned chunks can work in a pinch. Adjust simple syrup to taste based on the sweetness of your pineapple juice.Make mint-infused simple syrup by adding 10 mint leaves during cooking for extra mint flavor.Double strain the mixture if you don't want small mint pieces in the final drink.