Can an Airtag be connected to 2 iPhones?

You cannot pair an AirTag to a second iPhone, but the original owner of an AirTag can share the AirTag with you as long as both of your iPhones are updated to iOS 17 or later. Here's how your wife can share the AirTag with you after pairing it to her iPhone:

1. Open the Find My app  on your iPhone, then tap Items.
2. Tap the name of the AirTag or item you want to share, then tap Add Person below Share This AirTag (or Share This Item).
3. Enter the Apple ID of the person you want to add.
4. To add more people, tap .
5. Tap the name of the person you want to share with, then tap their Apple ID.
6. Repeat steps 3 and 4 for each person you want to add.
7. When you’re finished adding people, tap Share in the top-right corner.

Your iPhone should receive a notification that your wife wants to share an AirTag with you. To see the invitation in Find My, tap Items, then tap Add.

You can't do this - it attaches to one AppleID only. However, with iOS 17, you can now SHARE it with another. From your wife's iPhone, select the AirTag you want shared and share it with your Apple ID. Approve it on your iPhone and that should be it.

Good luck.