I'm not sure of exactly what you are trying to do.

The CTA would, for example, heartily disapprove of sharing your monthly pass with a few dozen of your closest friends and family. (Or any of your friends and family, for that matter.)

But, basically, no. When you use Google Pay, for example, you have to select a credit/debit card from your wallet. When you go to pay, your phone does not send that credit card number to the card reader. Instead it sends a generated number known as the PAN to the card reader. Even if both you and your friend both had the same card in your Google Wallet, your phones wouldn't be sending the same PAN and so they would look like different cards to the card reader.

As far as Metra goes, they actually store the tickets on your phone to prevent ticket-sharing.