In game Detailed Info then should be changed to reflect that then if it not a bug. the Description say "This boost is double in strength for pets", but the Detailed Info "12% Strength to X on target". Which by that logic, double the power of the provided info would be 24% not 12% for pet, and the player would get 12% not 6%.
And as stated on Mids it shows you getting the 12% bonus from it.