Quality chart is outdated
here's a crossbow one with talent, daunting, and grandmaster. https://i.imgur.com/EDLWd0y.png
Grade/Quality: Balance+5, Crit+5, Max+2, Min+2, Dura+3
Skill Rank: Balance+2, Dura+2
Active Talent: Min+1, Max+2
GM Bonus: Min+1, Max+1
1 - The stat bonuses you got for quality are exactly what you get for x-grade on the chart.
2 - The second line is the inherent flat stat bonuses you get from your Carpentry rank, they're listed on the page too.
3 - The third line is the bonuses you get for having Carpentry as your active talent, it's listed higher up in the page.
4 - The 4th line appears to be your active GM effect for carpentry.
I understand now, however I would think higher quality grades for carpentry would be named to differentiate between X grade and GM+master x grade. seems a little lacking.
The grade system is not just for carpentry, it's the same item quality system that the game uses for other things too (like cooking, blacksmithing, tailoring, even dropped weapons from monsters and synthesis). In addition what if somebody has the GM effect on but doesn't have carpentry as their active talent? Then they'd get those stats minus the third line.
So the bonuses are listed separately because they have separate sources.