Gave it more thought. I'm thinking he gets -3 since, as you noted, the ball was actually recovered 6 yds from where he caught it, so possession didn't officially change until TB picked it up, therefore the last person to have the ball, Amendola, is responsible for the ball until that point. If the Rams had recovered it wouldn't make sense to credit him for a 3 yd reception if, after the play ended, the Rams had LOST 3 yards.
Hopefully someone can confirm.