The Ayurvedic adage to not consume heated honey stems from honeys traditionally coming from the forest where there was concern that the bees may have harvested from plants containing toxic compounds that may be released when the honey was cooked.
Modern understanding of why honey should not be heated, stems from honey producing Hydroxymethylfurfural (HMF) when heated. The production of HMF is a natural process dependent on temperature and time. For example, HMF is only produced when the honey is heated for several hours at incredibly high temperatures. When making tea, the temperature of the water and the length of time that a teabags remains in a cup make the production of HMF negligible.