I redeemed my my google play gift card on my computer by an accident?

It doesn't matter if you did it on your computer or not. If you have a google play account, your money will be on any device if you are signed into the account.

If you have one google play account, linked to your gmail, you can spend the balance on either the computer or the device.

Your Google account should be synchronized between your computer and device, meaning it does not matter where you claim your Play Store credit as it ends up in the same account.

If you have different accounts on your PC and device, there is no way to transfer the credit, you'll have to log into your computer's account on your device and purchase your apps/movies/music/etc with the account the credit was redeemed on.