Please note that Freepik and Flaticon are different projects from the same company. Although your user account will be valid for both websites, premium memberships do not work in the same way. If you acquire a Premium plan for Freepik, this will only give you access to the premium resources from Freepik and the other way around.
If you want to have access to the premium features for both sites, you will need to buy a Premium plan for Freepik and another Premium plan for Flaticon.
With regards to the payments, since both sites are part of Freepik Company, the confirmation emails about your subscription and the charges that will show in your bank/Paypal statements will all come under Freepik Company name, even if you have bought a Flaticon subscription.