radonc1

I was hoping someone else would answer this before me

You can use Venmo to send money to anyone you wish, as long as they are on your list of approved payees. I use Venmo to send money to my kids, and they pay me on a routine basis into my account. However, my account is attached to a bank checking account and all funding (either in or out) goes through it if there is not enough money in my Venmo account to fund a payment.

However, I think that you are asking whether you can send money to your wife using a CC. The answer is yes, as long as you are willing to pay the fees to both your CC company for using it to obtain cash (for which they will charge you between 27-37% interest rate from the moment you get the money sent to your SO) as well as any fees attached to making the transfer. Then you need to add Venmo's fees for using a CC for payment, which they will happily do for a 3% fee on the money you use to make the transfer. I would highly suggest that you carefully read both your CC T&Cs including fees for using your CC to get a cash advance as well as Venmo's fees for using a credit card to transfer money.

My suggestion to you is, if you need to go the route of using a cash advance on your credit card, that you get the cash advance as a stand alone event and then take the money you received from the credit card company and deposit it into Venmo prior to making the transfer to your wife. That way, you will avoid Venmo's fees for making a payment using a credit card.
However, I would not make a habit of doing this, not because of the ridiculous fees involved, but because Venmo does not like people playing games with them and has a nasty habit of shutting down accounts for such behavior as described above if done too many times in a short period of time.