You have a nikasil coating on your cylinder walls
You can't just bore, hone and assemble. You have to have a nikasil coating applied to the cylinder walls before reassembly.
Your model year of BMW has the nikasil coating.
I would not simply hone your cylinders, attempt to the coating, it may be required to put then next overbore size of piston in. If you did require an overbore the piston sizes come in .25mm step increases in bore diameter. You would also, of course, get new rings with the pistons.
You have two paths
Clean the piston and rings. Take the rings off when you do this. Make sure they go back into the same landing of the same piston upon reassembly, the rings wear into the piston and match.
Get the next size overbore piston and rings and send out your cylinders and new pistons for the machine work. If you take it to an independent shop they will have a relationship with a firm that does the coating and will usually be cheaper than going to the dealer. From there, reassemble and smile.
You can make your decision by measuring the bore of your cylinder at the top, middle and bottom of the piston stroke. If the diameter exceeds service limits in any of the locations then that can drive your decision to bore and rebuild or not. Hope this helpful.
Diagram of Components
Notice the lower image, the rings go in particular grooves on the piston. These grooves are called landings. You will want to ensure that you put the ring in the landing it came from. All of the components are wore into one another and as a result have matching wear patterns. Placing the rings on the incorrect ring or landing could accelerate the wear of the particular component and lead to an early failure.