Well, depends on what kind of tea it was. Tea leaves in general aren't very good for rabbits, but most herbal teas are actually very good for rabbits and are in fact commonly used as intestinal remedies.
If there was sugar in the tea, that's obviously not very good for you rabbit, but it won't cause any emediate serious harm.
I would just keep an eye on him. Make sure he is still eating and drinking and remaining active. If he becomes lethargic, loses his appetite, and/or has irregular shaped/colored feces, than that would be a sure sign to get him to a vet right away.
However, personally, I do think your rabbit should be fine.