I am sorry you did not state in your initial question that your city had rent control. Not every city in California has it. The statute they are quoting you is not correct. That is merely the section that states they have to give you 90 days notice of any increase.
Be aware that in a mobile home park, there are many expenses that the landlord has which are exempt from the rent control laws. For example, if the real property taxes on the park go up, they can pass that thru to you. If regulations on how the park has to be run change, they can pass the extra costs on to you. They can even charge you extra for their expenses associated with complying with the rent control laws! You need to find out their justification for the increases. If there is none, you can complain to the rent control board.
Attorney
23 Years as attorney, licensed NY and FL. Former US ATTY.