Your link with your companion creature allows you to share your magic with it.
Benefit: When you are adjacent to or sharing a square with your companion creature and that companion creature has this feat, you can cast a spell on yourself and divide the duration evenly between yourself and the companion creature. You can use this feat only on spells with a duration of at least 2 rounds. For example, you could cast bull’s strength on yourself, and instead of the spell lasting 1 minute per level on yourself, it lasts 5 rounds per level on yourself and 5 rounds per level on your companion.
Once the spell is cast, you and the companion creature can move farther apart without ending the effect.
Pathfinder Roleplaying Game: Advanced Class Guide © 2014, Paizo Inc.; Authors: Dennis Baker, Ross Byers, Jesse Benner, Savannah Broadway, Jason Bulmahn, Jim Groves, Tim Hitchcock, Tracy Hurley, Jonathan H. Keith, Will McCardell, Dale C. McCoy, Jr., Tom Phillips, Stephen Radney-MacFarland, Thomas M. Reid, Sean K Reynolds, Tork Shaw, Owen K.C. Stephens, and Russ Taylor.