Is this the same wallet as the one in the Creta app or on my phone?

No. There are three separate wallets, each holding its own keys on its own device: this extension, the wallet built into the Creta Games & Clubs desktop app, and the one in the Creta mobile app. Setting up one does not create the others, and each has its own password.

If you want one wallet everywhere, import the same seed phrase into each. They will then derive the same accounts and show the same balances, because they are reading the same addresses on the chain.

Your Creta account stores whichever wallet address you most recently connected, so connecting a different wallet on one Creta site changes which address the others see.