re-freezing green tea?
The concern with food is that if the food spends too much time above the danger temperature (40°F) then bacteria may grow, and if you then freeze it the bacteria will be there waiting to harm the final consumer. However, the USDA says that food thawed in a refrigerator for less than a few days can be safely refrozen.

Assuming these leaves are dry, this doesn't apply here: things won't grow on the tea while it's warm, and freezing won't lock in anything dangerous. So, freeze away.