I've always interpreted it the same way as you - the bonuses only apply to rolls for Dread. For me, the word "additionally" is key.
This Virtue may need further clarification on how it interacts with the 'Invisible' Fell Ability that has been reintroduced in the Moria Alpha (it was also in a pre-release version of Tales from the Lone Lands, but Houseless Wraiths were changed to an environmental hazard in the final version). According to the Invisible Fell Ability, Player-heroes lose (2d) on Awareness, Scan and Attack rolls, etc., against invisible opponents. But the Against the Unseen Virtue is described:
"Elves can perceive creatures that dwell in the wraith-world, be they spirits or ghosts, even when they are normally invisible to the eyes of the living and appear only as a chilling whisper of voices." - my emphasis.
Perhaps the Invisible Fell Ability should state that it doesn't apply to anyone with the Against the Unseen Virtue.
Elves can perceive invisible creatures because they can obtain the Magical success required to reveal such creatures:
Against the Unseen does nothing in this regard.
It is not our part to master all the tides of the world, but to do what is in us for the succour of those years wherein we are set, uprooting the evil in the fields that we know, so that those who live after may have clean earth to till.