The new rules for the licentiate-salary increase is valid only for students admitted after 30/4-2017
As an employed PhD student you also work according to the collective agreement. The agreement contains for example information about your right to vacation (see next section for details), about getting saved vacation days paid out at the end of your contract, which days are holidays etc.
When working in Sweden (as for example an employed PhD student at Chalmers) it may be very beneficial to join a labour union. You need to pay for labour union membership, but it will provide useful support for all types of work-related issues that may occur during your employment.