Is it wrong to add another bike lock to a random bike that already has a lock on it?

Yes it is wrong, also illegal - you have maliciously blocked someone from using their property.

Years back we were on an island basked club. It was late in the day and we took our sailboat back to the city and moored it at my FIL's slip at the city - he called and left a message telling the manager of the slip that this was our boat and explaining it..

I got down the next day to see a heavy chain and two pad locks - locking our boat to the dock. I was pissed off - I had tools and I broke one of the locks. Our club manager called the marina manager - and that manager went nuts... too fucking bad... I was magnanimous and took the idiot back his chain and suggested that locking up someone else's boat was NOT a good idea.

Now theres an idea 😏😂

You mean a bike you do not own?? 🤨