Is Aquaman related to Neptune or Poseidon?

Is Aquaman related to either Neptune or Poseidon?

No

neither of them.

No, he is a King not a God.

Neither. He's Atlantean and they're Roman and Greek respectively. So actually, Wonder Woman's Uncle(s)

Aren't they the same God any way but no he isn't.

No.

And no, Aquaman doesn't worship Poseidon. They don't even like each other.