You would say, "Quando tu sia morto, mi DARAI la carta d'autobus?"
"Sia" because "quando" refers to a hypothetical condition in the future, so you have to use the present subjunctive. And "darai", because it's the simple future. To use the conditional, you'd have to say, "Se tu FOSSI morto, mi daresti la carta d'autobus?" Hope that helped!