Flying PHX/MIA last night. First 20 minutes or so of flight rough air but then smooths out and seat belt sign comes off. I'm in 8A. No beverage cart. Throughout the flight at the slightest bump seatbelt sign goes on but while off no beverage cart and soon as it goes on FA makes an announcement they can't do service. Finally with about an hour left while the seatbelt sign is off, and has been off for half an hour, F gets their meal and Y FA comes around with a bottle of warm water claiming it's very dangerous for them to be up (while the seatbelt sign is off) and says we can only have half a cup of water due to "safety reasons."