Unless the manufacturer explicitly says so, you should assume that your comforter cannot be ironed. If you need to get wrinkles out of your comforter, you can try one of the following methods:
Using distilled water, spray the comforter with a spray bottle and smooth out wrinkles by hand. Take a hot shower while your comforter is hanging in the bathroom. Set your machine dryer to low heat and place your comforter in it with a wet towel and some dryer or tennis balls.