You have not stated from which date you are already on maternity leave. The Amendment Bill was introduced on 8th August 2016. However, in the Amendment Bill, it is clearly mentioned, "It shall come into force on such date as the Central Government may, by notification in the official Gazette, appoint." The formal Gazette is yet to be issued.
Generally, the law applies as mentioned in the notification. Since you are already availing of the benefit, in my opinion, you are entitled only as per the previous notification's entitlements.
One more point to consider is that if you are covered under ESI, then the same will be paid by the ESI Office only. Your employer is not legally bound to pay anything against Maternity Leave. If you are not covered under ESI, then only you are eligible to get benefits from your employer. Ms. Sweta has explained how to get benefits from ESI (she faced a lot of problems in getting the benefits, so she has shared her real experience).
Regards