Hello. My name is Michael. I can help you with your question.
In order to reset a gmail password, you must use the alternate email that you already have on file in your account. If your yahoo email is what you have on file, that is what they will send to. This is by design for security. If you no longer have access to the email on file, you can continue through the reset, and selecting that at the appropriate time. It will take longer, but if you do that someone will get back to you within 48 hours usually.
You didn't mention that. But the same applies. It will send to the email you have on file as your alternate. That is the only email you can reciver to.