Rage Prophet's Savage Seer ability says:
Quote:
|
Originally Posted by Savage Seer
A rage prophet's class level stacks with barbarian levels for determining the effect of rage powers, and with oracle levels for determining the effect of oracle revelations and his oracle's curse. This does not grant additional abilities.
|
(emphasis mine)
That means your levels in Rage Prophet add to the other two for those abilities, as you've seen. It doesn't mean your levels in Barbarian/Bloodrager/etc. add to Oracle or vice versa.
The definition of "class level" is available on the AoN at
Common Terms under Level.
Hope this helps.