You drive a public bus, and you're worried about being stalked by an AirTag??? wait till you hear about bus schedules, since someone will be able to pre-stalk you and know where you're going to be at certain time in the future.
Also depending on what company you're driving for, your real-time bus location could be available online.
you get the notification if the tag hasn't seen the owner's phone in a certain amount of time.
don't count that "traveling with you since 7:30" as the exact time the tag entered your bus, They could have gotten on the bus earlier, and that was just the first ping you phone heard. The tags send out pings at random times. Or that's where they could have gotten off the bus. and your phone didn't care that it was traveling with you before, since the owner was with the tag.
now lets go through the steps in your situation.
- Someone accidentally left a bag on your bus with an AirTag in it.
- your phone alerted you to that fact that there was an airtag traveling with you.
- you found the tag
so it seems that apple's anti-stalking efforts actually worked.
hopefully you didn't mess with the battery in the tag, and turned the bag into lost and found, or whatever you're supposed to do with found articles. And the owner of that bag might be able to find their property.