Yes. The rating is to stop the fitting being damaged by too much heat from the bulb. The cabling (both in the fitting and supplying the fitting) won't be an issue. As low energy bulbs don't generate anywhere near the same amount of heat then you can use a higher wattage equivalent. Don't forget the real wattage rating of a low energy bulb is well below that of an "normal" incandescent lamp.
Try an 11W low energy bulb, this should give a light output similar to that of a "normal" 60W bulb.