No. It only adds an additional degree of success in the cases where you actually succeed on a test.
My fiancee's Slaanesh Renegade, who was also the socialite of the group, put her special ability on Fellowship, on the basis that it fit the character best. Plus, when you get to higher levels, having more DoS for shooting isn't all that much more useful, given how high you can get your To Hit bonuses.
~Yea, Tho I Walk Through The Valley Of The Shadow Of Death, I Shall Fear No Evil~
Rogue Trader, Dark Heresy, Deathwatch, Black Crusade + Only War Playtester
Star Wars: Edge of the Empire Playtester
I do not speak in any official capacity for FFG, all my posts are my own opinion, speculation, etc.
One of Three Founders of Dark Reign