I'm not sure they'll give any bonus at all this time - but if they did, I'm thinking they'll be their own unique perks like magazines. I can't see them adding additional ranks to existing perks, since those ranks have level requirements - seems like that would undermine the leveling system.
Some will add an additional rank... to a perk granted by a magazine. As in the barbarian perk has 10 ranks, since there is 10 grognak the barbarian comics. Other magazines will grant perks, some will have multiple ranks, some will have a single rank. Just like the regular perk chart.
Not sure what the Barter Bobblehead would do since that is already covered by the Cap Collector perk. The Agility and Charisma Bobbleheads seem pretty clear in what they would do.
It seems more like they cut into part way of putting bobblehead from their inventory to the display. Also in one of the gameplay videos, there appears to be a blurred bobblehead on one of the desks when talking to Preston Garvey. It certainly looks like it has the yellow hair that Bobbleheads have.
It is far more likely that magazine perks and bobblehead perks will be separated so there is 10 Grognak the Barbarian comics that increase melee critical attacks and the Melee Bobblehead that increases standard melee damage.
I meant that the magazines are separate entities from both bobbleheads and regular perk chart perks.
I hope they're placed randomly across the world instead of hand-placed.
This would be cool. There's a well made New Vegas mod which adds them to the world in semi-random (but still contextually appropriate) locations.