Using a different account for writing reviews on Play Store
Google Play write a review does not say that your review account has to be the same as the account on the phone. You can have multiple accounts on your device. 

So I would conclude what you are doing isn't wrong, but I see no advantages of doing so. On the contrary, it may cause confusion. Let's say a developer responded to your review saying that a paid app isn't working and asks you for app logs, they would see a different account