Thresh Passive and Thorn Mail Passive Interaction

I'm curious to as whether the passive of soul collection counts towards the Bonus Armor passive on the Thorn Mail Item. Thresh gains armor and ability power from his passive and in Thorn Mail bonus armor is counted in the damage reflected back. On Thorn Mail the passive it quotes: (Bonus Armor is armor from Items, buffs, runes, and masteries. It says nothing about bonus armor that may come from the passive of a Champion. I know buffs are displayed on the bar above the skills / abilites of Champions. The Thresh passive is also displayed there, so does this count as a buff?

So in all I just want to know if the armor from his passive counts as bonus armor that interacts with Thorn Mail.