How long should I wait to smoke/drink after mono/strep/tonsillitis?

For ever. You have no need to smoke, ever. It's bad for you before, during, or after mono/strep/tonsillitis. If you have stopped for more than three days because of your illness, the physical addiction is already broken and any cravings you feel are just habit. Stay a non-smoker, for the rest of your life.