Main difference, it is appropriately sized... ie, you can get a 500ml Platy or a 1000ml Platy, but a bottle of wine is typically 750ml as is the wine bladder. I have one, I use it for whisky, it works great.
Beyond size it is admittedly marketing and market expansion or cross-over. Could make a nice little add-on sale at the local wine shop, maybe someone going on a picnic, tailgating, somewhere where glass bottles aren't allowed. By making them look different and making the distinction that they're good for wine, more people will be aware of the possibility. And they look better... Not saying it's a big deal in any way from an end-user perspective, but from the company perspective probably a wise move, more acceptable "looks" from the wine crowd.