Drinking tea before bed is okay as long as you avoid drinking the caffeinated types of teas which could keep you awake instead of helping you sleep.
If you drink the non caffeinated tea then the tea could actually help you drift off to sleep faster and help you stay asleep.
I drink some Yogi Bedtime tea that I buy on Amazon and it helps me to fall asleep naturally and helps me stay asleep.
The warm tea before bed as long as it's the non caffeinated Variety has a good natural calming effect which helps people fall asleep and stay asleep.