No, only 1 phone number can be added.
When setting up your home monitoring system, you can only add 1 phone number. During an alert, Noonlight will contact that phone number only. There is no way to add a backup phone number (ex. you didn't answer the call, so your spouse is contacted next).
Make sure the primary person on the account, who is most likely to answer the phone in the event of an alert, has their contact info on the account.