The guest card is included in the taxes and can be requested at reception on arrival.

With the guest card you can travel free of charge on buses in the town, free of charge to the museums in Chur, free of charge to the public swimming pools and
you receive a 50% discount on the cable car to Brambrüesch.

You also receive:

20% off court hire for Padelta in Chur
10% discount on the zipline in Pradaschier
10% discount for the salt cellar in Chur
20% off English public guided tours of the old town in Chur

We will be happy to provide you with detailed information on arrival. 

Here you will find the public page with all the offers of the guest card:
https://www.chur.graubuenden.ch/de/angebot/gaestekarte-chur