Sorry - to clarify my previous answer.
Some companies offer up to a certain amount towards housing and pay the landlords directly - you then do not get to pocket any underspend.
Others simply pay a separate housing allowance per month as part of the overall salary package, along with other allowances such as transport etc.
These allowances can be spent on what you like and are listed separately so that your annual salary is as low as possible on your labour contract - this is so that the company can pay you a lower end of service gratuity (as this is based on base salary)
Hope this is clearer!!
If you choose to take the housing allowance in cash, then yes... both EK and EY give you the option...
I heard in the case of EY, the provided accommodation is not really an option even though its offered, as they don't have much inventory of company provided places available, and when they do come up, are usually given to pilots first...