Sparkling water can be just as hydrating as still water.
Sparkling or carbonated water is made by dissolving carbon dioxide in water, creating carbonic acid. This process just adds bubbles.
The only thing with guzzling sparkling water is you may get gas and burp especially if you drink it fast!
Although, still water is preferable to sparkling water post-workout as the bubbles may create a sense of fullness and may cause you to drink less than your body requires.