It must have been the gardening people - talked to the neighbor who celebrated a party in the garden yesterday. He said they left a camera and some presents outside over night. Everything still there - but my bike is gone.
Someone enter the property targeting just the bike. No random theft of anything valuable
Maybe they went for a ride... and they will come back.
Take their camera, and when the are back ask for the bike... if they are the real ones, they will feel complicit. If they don't at least you have leverage.
If the are the true ones, make the camera appear somewhere, and then tell them.