is the trait
Strong Arm, Supple Wrist Benefit: Whenever you move at least 10 feet before making an attack with a thrown weapon, you add 10 feet to the range increment of the weapon thrown. Restriction: You can only gain this benefit once per round.
and/or the feat
Opening Volley (Combat) Benefit: Whenever you deal damage with a ranged attack, you gain a +4 circumstance bonus on the next melee attack roll you make against the opponent. This attack must occur before the end of your next turn.
compatible with an Alchemist's bombs?
Yes, they should work.
Bomb (Su): "Thrown bombs have a range of 20 feet and use the Throw Splash Weapon special attack. Bombs are considered weapons and can be selected using feats such as Point-Blank Shot and Weapon Focus."
Throw Splash Weapon: "A splash weapon is a ranged weapon that breaks on impact, splashing or scattering its contents over its target and nearby creatures or objects."
Thrown Weapons: "The wielder applies his Strength modifier to damage dealt by thrown weapons (except for splash weapons)."
It's a weapon, a ranged weapon, and more specifically a thrown ranged weapon. In order to attack with a ranged weapon, you must make a ranged attack.
Strong Arm, Supple Wrist requires making an attack with a thrown weapon, which you must do to attack with a bomb.
Opening Volley requires that you deal damage with a ranged attack, which you do with a bomb (assuming you hit or splash anything).
Thanks for responding and the insightful answers.