Barking behaviours and neighbours who can't tolerate barking noise.

It is said that when a pet dog misbehaves, it is the fault of the owner.
If there is one behaviour that I am not able to correct, it is the barking. Specifically Jon's barking.
Is it bad behaviour that a dog barks at postmen, garbage men, flyer distributors, cats and dogs walking past? I want to control Jon, but it is not possible to check him on this behaviour as I am not at home during the day from Mon-Fri.
However, if there is one funny barking behaviour that Jon exhibits, it is when:
1) I enter the car - which is parked outside of the house - and start the engine.
2) When I come home with the car.
3) My immediate neighbour starts his car engine.
4) My immediate neighbour comes back home.
The tone of the bark for 1), 3) and 4) are similar. It is intermittent, 3-4 quick barks every 5 seconds, lasting in total up to 20 seconds. For 2), it is more excitable sounding. Is it a welcome home message?
Jon rarely barks at night, except when a cat passes by.

Because of this, especially for the said instances related to 3) and 4), my neighbour (lets call him by his acronym FKK) is irritated by it. He has done nasty things to Jon ie spitting and throwing pebbles. And this pisses me off too. And as a result there is a feud between both of us.
Just last week, I got a warning letter from the local council - MPSJ - to inform me that someone had lodged a complaint, and advised (not insist) that I put a muzzle on Jon. I went to see the person who handled this complaint, and explained my situation to him. He agreed that it is normal for dogs to bark at postmen etc. I told him that every one of these neighbours here has stayed here no less than three years. Reading between the lines, this complainant had decided to lodge a complain after keeping quiet for so long. Never once had I been approached by any neighbour about the barking issue. Hence I hypothetically conclude that this person has made this issue a personal agenda.