This looks like it is a similar bug to the one affecting the other crafting feat merchants - if you have purchased Brew Potion from another npc then you no longer have the option to purchase the upgraded wand crafting.
(https://imgur.com/3clTzTz.png)
You get the conversation option to ask about it, but the only option available when you have the gold on you is "I see."
Weird, my character definitely learned brew potion from the Ticker merchant first. Before having no trouble learning wand crafting from the npc mentioned above.
This might just be an issue with the tutor in the Peerage ward.