I am not aware of any research into fluorescence being an attractant for prey. It seems an unlikely proposition.
When there is twilight or moonlight and fluorescence is going to be far less significant that the source of the light - the moon and the sky. If the zooplankton where attracted to the light (and many are), they are going to be attracted to the water surface where the light is much brighter.
I have dived many times at dusk and at night under a full moon. The light from the surface dominates and I have not noticed any fluorescence from corals even when wearing a barrier filter*.
Another thing to consider is the lack of fluorescence in azooxanthellate corals. If it was a benefit for prey capture, why don't these corals fluoresce?
* Barrier filters manufactured by
NightSea which are used in conjuction with Exciter filters over a light source for detecting fluorescence. The Barrier filters block shorter wave light and the Exciter filters only allow shorter wave light.