Its a handy bag to have. Recently I have seen these PVC ice bags being used at a few trade tastings to chill wine instead of ice buckets.
It makes a neat gift as it can be used to carry a bottle, chill it and after use you can fold it away.
I've used these a couple of times when dining at neighbourhood hawker centres with friends. Its a convenient item to have. Just buy some ice and add water into these bags and your white wines get chilled to the right temperature; and they take up less space at the table than ice buckets.
Do keep a look out for these bags next time you go shopping for wine accessories :)