This is quite possible.
As a student, you are normally entitled to the same benefits that a regular employee also receives. However, bear in mind that an employer may choose to offer luncheon vouchers only to a certain category of his employees. Consequently, it is perfectly possible that part of the staff does not receive luncheon vouchers. Example: an employer may choose not to grant luncheon vouchers to employees who have only recently joined his service.
It is therefore best to ask your employer which conditions you have to fulfil in order to obtain luncheon vouchers.