
heyyon |
Unfortunately not.
There are some useful items that are involved with Aid Another, though.
Gloves of Arcane Striking.
Ring of Tactical Precision.
Benevolent Armor/Weapon.
There are also some awesome class bonuses.
Dragon Order Cavalier
Cavalier - Honor Guard
Battle Herald
You can already get your aid another bonus for attacks up to about +13 and +14 for AC. I think that's more than enough!

heyyon |
Ohako,
If your Eidolon can use it, Ring of Tactical Precision is kinda nice. Not sure if your eidolon will get the feats, but RoTP can be "charged" with a teamwork feat that equipping the ring bestows. Quite useful. It also bumps the Aid Another bonus of the giver or receiver... Pretty sure that would stack if you and your eidolon each have one on and the eidolon uses Bodyguard on you or vice-versa.

Taku Ooka Nin |

Keep in mind that while traits are roughly 1/2 the power of feats, Paizo has openly stated that they do not want traits to become additional power-creep any more than they already are.
So, realistically: no, there is not a feat that does what you are asking for. You might be able to find something in 3PP, but it simply does not exist in Pathfinder. Your GM might allow you to apply the trait bonus to a familiar, in the case of a Valet or something, however.

heyyon |
Also worth noting:
Helpful is *not* a bonus. It takes your base of +2 for Aid Another and increases it to +3 or +4 if you use the Halfling specific trait. Something else can modify that increase and they will stack; however, Helpful won't stack with something else that says "replace" or "instead of."

LoneKnave |
Which is kinda silly.
"Hey, here's something you can do in combat even if you can't cast spells that's not attacking or making a combat maneuver that you'll fail anyway"
"Wait a moment, that sounds too good to be true! Let's make scaling it incredibly difficult, always replacing the base bonus instead of adding to it."