First of all, "room" temperature is not necessarily bringing a wine to the temperature of the room, especially when this temperature can be more than 20 C. In fact, it means bring a wine to a temperature 16/17 C. On the other hand, it is wrong to think that only an opened bottle can be brought to room temperature since heat exchanges occur through the bottle also.

The lower the temperature is, the more wine tannins are highlighted. This explains why red aged/wines, full-bodied wines have to be brought to room temperature. If they are chilled too much they may end up tasting like only light red wines should be cooled.

The higher the temperature is, the more mellow character of a wine seems heavy, the acidity "biting". This explains why dry and mellow white wines are cooled.

Carbon monoxide has a tendency to burst out with more violence when the temperature is high. Champagne and other sparkling wines are served very cold so that gases are barely perceptible and therefore the wine pleasant.

Also see :- Tasting & Drinking.