Can I report a taxi that picked up more passengers?
Did the taxi do something to you personally?
No, it's a violation of the rules.
If someone is in violation of the rules, they should be reported so that the boss can take proper action. The driver might learn something and be able to keep his job longer.
I don't really agree with the rules and I don't want to hear about obeying rules.
If it is a problem that someone does not follow rules it is ok to report them.