What is the appropriate use for the term bhante?
From the Mahaparinibbana Sutta:


  "And, Ananda, whereas now the bhikkhus (monks) address one another as
  'friend,' let it not be so when I am gone. The senior bhikkhus,
  Ananda, may address the junior ones by their name, their family name,
  or as 'friend'; but the junior bhikkhus should address the senior ones
  as 'venerable sir' or 'your reverence.'
  
  Footnote: "Friend," in Pali is avuso, "venerable sir" = bhante, "your
  reverence" = ayasma.