In a large pitcher, combine the white wine, coconut rum, and pineapple juice. Stir well to mix the ingredients together.
Add the diced pineapple, strawberries, and sliced oranges to the pitcher. Gently stir to incorporate the fruit.
Refrigerate the sangria for at least 2 hours to allow the flavors to meld. For best results, chill overnight.
Just before serving, add the soda water (or lemon-lime soda) to the pitcher and stir gently.
Fill glasses with ice cubes and pour the sangria over the ice. Garnish with additional fruit slices if desired.