Tea refers specifically to a beverage made from the leaves of Camellia Sinensis. I won't go into the finery of the etymology of the word, but the word tea comes from the Amoy tê or Cantonese chàh both referring to the camellia sinensis plant. Without this root, we would use some different term to refer to herbal infusions and steeped drinks.

My point is you can't have herbal teas without having actual tea, therefore its logical Randland has tea.