the-witcher-3
Just won the high stake Gwent tournament in Novigrad and completed the quest. After each match I received a message that I won a new card, but there was nothing on my deck.
I thought that the cards would eventually be added after I completed the whole quest, but still, no cards.
What cards could you win?
I completed that particular bit a few hours ago. If I recall, nothing happened after I'd beaten him, I'm pretty sure it was just to signify that you could play gwent against him.
According to this comment on Reddit, the cards are available from the Shopkeeper you rescue from the Griffon during the tutorial, as of patch v1.04.
Having checked, it seems that that shopkeeper now has the four cards that I'd missed - namely:
After being rescued, the shopkeeper is located to the west of Woesong Bridge, in White Orchard.
Best Answer
The 3 'cards' you earn are all leader cards, which is why you don't see any new cards that can be added to your deck.
In particular, these 3:
Emhyr var Emreis, The Relentless
Francesca, Queen of Dol Blathanna
Eredin, Destroyer of Worlds