Showing up as a guest with a bottle of wine in a pretty bag is polite. Showing up at that same party with a clear, waterproof bag full of ice and chilling that bottle of wine is beautiful. Typically I would not suggest chilling wine as much as possible, but the odds are that the wine you are bringing was not purchased off the top shelf, more like hidden behind the counter. Not that there is anything wrong with that.
Product Page (£4.99, about $8.60)