Here's how it could help:
1. Yoga is exercise. Exercise not only burns fat but it also helps to tighten and tone your muscles.
2. Yoga helps increase your circulation and blood flow which helps get rid of cellulite.
I don't think yoga is the best kind of exercise but it's way better than doing nothing at all. My anti cellulite secret was a combination of exercise, dry brushing and cellulite cream: http://www.cellulitetreatment.org/cream.html
If you decide to give yoga a try to see if it helps with cellulite, please come back and let us know if it works for you!