You Have That Power Too

Way of Tutelage: 10th, 11th, and 17th level The bond between you and your companion has strengthened. When your companion is within 10 feet of you, and either you or your companion casts a force power that would affect only one of you, you can instead have it affect both. At 11th level, your companion must be within 30 feet of you to benefit from this feature. At 17th level, your companion must be within 60 feet.

Granted by Way of Tutelage at 10th level.