Clarification on Rage Power bonuses

[Serisan]

Does the following base the bonus on character level or Barbarian level? This is an ambiguity that is not particularly cleared up anywhere in ancillary text.

Reckless Abandon (Ex): While raging, the barbarian can take
a –1 penalty to AC to gain a +1 bonus on attack rolls. The AC
penalty increases by –1 and the attack roll bonus increases
by +1 at 4th level and every four levels thereafter.

[Eric Clingenpeel]

Serisan wrote:

Does the following base the bonus on character level or Barbarian level? This is an ambiguity that is not particularly cleared up anywhere in ancillary text.

Class abilities based on level always refer to class levels unless it specifies character level. So in this case it is barbarian levels.