Comma between correlative conjunctions joining two dependent clauses?

Hello there,

my question concerns correlative conjunctions like neither... nor...,

not only... but also... etc.

I have understood that normally correlative conjunctions are not separated by a comma, except for the case in which they join two independent clauses. Both of the followng sentences are correct:

1. John wants not only a car but also a new computer.

2. Not only does John want a new car, but he also will buy himself a computer.

Only the second sentence needs a comma before "but", because "not only... but also..." joins two independent clauses together.

My question aims at the situation when a correlative conjuction joins

two dependent clauses like in the following example:

John will leave when either he has finished his work, or somebody else is doing it for him.

Where "he has finished his work" and "somebody else is doing it for

him" are both, to my own understanding, dependent clauses, indicated by the subordinating conjunction "when".

Can I put this last example sentence the way I have?

Is the comma in it before the "or" correct or should it be left out?

Thanks for your answers.