I'd like to know as well. A lot of the references to dormancy and bromeliads come from very generic care sheets and I doubt it applies to the whole family; after all, many of them reside around the equator in very persistent conditions. Of course many do not and are in regions with somewhat defined seasons (Florida?) and I would imagine that they must have some response to the changes throughout the year. At the end of the day many species are pretty forgiving and I don't see the harm in scaling back watering and fertilizing in the winter months. If they're not getting enough water they're pretty quick to let you know with curling leaves.