Verified answer

The question means: Do you have a card for making telephone calls?

As for sirve you got me unless it is a mispelling for servir (meaning to serve)

Sirve means useful, like in "his attitude serves me as lesson" - Su actitud me sirve de leccion.

But also (as many other spanish words) it has another meaning: "Serve" when it refers i.e. "He serves a dinner" (el sirve una cena).

About the sentence "¿Tienes una tarjeta para hacer llamadas telefónicas?" - Translated to english will be : Do you have a phone card to make calls?

Sirve is the command form of servir - to serve

Translation of your sentence is - You have a telephone calling card.