So, putting vis in Talismans always confuses me, because I'm not sure it's clear. But this is how I understand it.
The first season, you open the item by putting in a number of pawns of Vis based upon the Talisman's material and size. In this case, Fiona's staff is Wood (base 2), and a Staff is Large (multiplier of x4), for a total of 8 pawns of Vis.
Now, because it's a Talisman, it can hold more Vis then its material and size would limit a normal Invested Item would. So, in her next season of work, Fiona (with a Magic Theory of 7 by this point) can put in an additional (MTx2) 14 pawns of Vis. The limit on how much vis she puts in is her highest Technique (Muto 12) plus her highest Form (Corpus 10), or 22 pawns.
Does that 22 pawns include the 8 she put in in the original season of work to open it up, or does it "reset" to the 8 pawns just to open it and an additional up to 22 to prepare it for enchantment? I'm thinking it's probably a total of 22 (8+14), but I'm feeling just foggy enough to think I'm wrong.