You are not bonding a weapon. You're bonding a celestial spirit. "enhance her weapon as a standard action by calling upon the aid of a celestial spirit" So your bond is with the spirit. Once per day (higher as you gain levels) you can put the spirit into whatever weapon you are currently holding to make it glow and gain bonuses for a short time (1 minute per level).
The key is, next time you use the ability you can apply it to a different weapon. I see no text anywhere that says otherwise.
If the weapon is destroyed while your bonded spirit is in it, you lose the ability for 30 days, but this has no bearing on using the spirit in whatever weapon you want when you call the spirit - it only has bearing on how soon you can use the ability if your currently bonded weapon gets destroyed.