The Tiefling variant heritage Oni-Blooded gains a +2 Racial Bonus to Wisdom.
The tiefling variant ability, traded for the spell-like ability racial trait, entry no 90 grants:
You gain an additional +2 racial bonus to your Wisdom score. (emphasis mine)
Does this mean an Oni-Blooded Tiefling that takes this variant ability gain a +4 Wisdom bonus, as the use of the word "additional" might imply, or is this intended for those tiefling who do not gain a Wisdom bonus from their standard racial modifiers?
Info for the tiefling heritages can be more easily accessed here, but should be available by scrolling down past the racial traits on the main tiefling page.