Upvote:4
It's not clear if you're suggesting that you took the wrong bag from the plane/airport luggage connection and took it to the bus, or if you put the correct bag on the bus and someone else took it from there.
If it's the former, then you should contact the airline as soon as possible. They have likely had the bag you took reported as missing, and probably have your bag in their possession. They will definitely be able to use the details on the baggage tag to track the correct owner of the bag.
If it's the latter, the officially the airline has no responsibility here, as the correct bags were taken from the airport by the correct passengers. They may be willing to assist with tracking down the owner of the remaining bag, but it's extremely unlikely they will outright give you their details (and I'm speaking from first-hand experience of a similar issue myself!), however they may be willing to pass your details onto the owner of that bag if they have relevant contact details.
At the same time, you should raise it with the bus company, and potentially even the police. Whilst it was likely an accident, the simple fact is that your bag has been stolen from the bus, so that is a police matter.