Per the main bond rules, bonds are strictly between player characters.
Bonds are what make you a party of adventurers, not just a random assortment of people. They’re the feelings, thoughts, and shared history that tie you together. You will always have at least one bond, and you’ll often have more.
Each bond is a simple statement that relates your character to another player character. Your class gives you a few to start with, you’ll replace your starting bonds and gain new ones through play.
Emphasis mine. The purpose of the bonds is to focus on the relationships between the player characters, which is why there are no particular rules for bonds (as a mechanic) between PCs and NPCs, or PCs and locations. This doesn't mean a player character can't have, figuratively, a bond with a place or an NPC - it's just in unruled territory, left to be handled by the players' own roleplaying.
Play for the fun, not for the rules
That said, no one is forcing you to stick to the rules about anything you want to change as a group. I see no obvious issue with allowing bonds to affect NPCs and locations, as long as players continue to manage PC-PC bonds too. In fact, the "Advanced Delving" chapter already has an example of a rule modification that allows bonds between PCs and NPC deities.
Some issues that may need to be addressed:
- Bonds as a mechanic may not correspond 100% with the players' perception of a bond as a narrative element. If a player wishes their narrative bond to be thought of as a mechanical bond, are they willing to resolve it eventually?
- Bonds are meant to be relationships, not directly objectives (even though resolving them is rewarded). Therefore bonds should stress out the emotional aspects of the whole ordeal. "I'm going to buy the Manor of Crawforde" is a rather flat bond; try "I had to sell my home at Crawforde to cover my debts, and I long to get it back" instead.
- If you want to treat bonds with NPCs and locations as mechanical bonds, they need to be capable of being resolved like normal bonds. "Rajan the shopkeeper is my brother" is neither very deep nor very likely to change, but "Rajan never paid me back for that time I covered his gambling debts" has both narrative significance and possibility of moving on with the story.
- The bonds are still primarily meant to be a mechanic for reinforcing relationships between player characters, so the players must agree not to overuse any non-PC bonds.
If you want to twist the rules really safe, grant the player the bond, but make it clear it's an exception, see how it works out for you and use it as a baseline when figuring out future cases like this. As long as it's just a single bond, it can't really rock the dynamic too much.