Lets take the following scenario. Someone is going around kidnapping young/weak wizards and taking their bonded items. These wizards are then incapacitated in some way to prevent them from gaining a new bonded item, and are not killed so the current bonded item remains active.
Could the kidnapper use UMD to use the bonded ability of casting a spell for themselves? If so what would the DC be?
It comes down to a question of which general or specific wording is more important.
The magic properties of a bonded object, including any magic abilities added to the object, only function for the wizard who owns it. If a bonded object’s owner dies, or the item is replaced, the object reverts to being an ordinary masterwork item of the appropriate type.
If a bonded object is damaged, it is restored to full hit points the next time the wizard prepares his spells. If the object of an arcane bond is lost or destroyed, it can be replaced after 1 week in a special ritual that costs 200 gp per wizard level plus the cost of the masterwork item. This ritual takes 8 hours to complete. Items replaced in this way do not possess any of the additional enchantments of the previous bonded item. A wizard can designate an existing magic item as his bonded item. This functions in the same way as replacing a lost or destroyed item except that the new magic item retains its abilities while gaining the benefits and drawbacks of becoming a bonded item.
You can use this skill to read a spell or to activate a magic item. Use Magic Device lets you use a magic item as if you had the spell ability or class features of another class, as if you were a different race, or as if you were of a different alignment.
For the purpose of this question, I do not care what kind of item the bonded item is, I am trying to go after its ability that lets the wizard cast any spell in their spellbook, not use it as a wand or something else. My thinking that the bonded item is a result of a class feature and UMD might be able to trick the item into believing you are its master as such.