How many users are allowed in an organization?

I know the official BitWarden has limits on how many can be allowed in an organization to 2 or 6.

Does VaultWarden have the same limits or how many people can you have in an organization? unlimited?

Vaultwarden does not check the amount of seats.
It also does not have a limit on Organizations of Collections on the server side.
It however could be Bitwarden has some client limitations, but not that i know of from the top of my head.

Depending on the size you may need to use a different database then the default SQLite, though SQLite can handle a lot of queries, also since Vaultwarden/Bitwarden is mostly read and not write it can handle a lot.