No - just need to pay i think 50AED on arrival and about the same on exit.
They will take UAE money but will give change in Bahraini dihnar, its a year or so since i last went and i *think* that was what i was charged. Not a lot really.
But they do ask for the hotel you are staying in and / or the mobile number of the person you are visiting.
Last time i went, they already had a mobile number plugged in for me.