There is a difference with Google Account and Google Gmail. Google Account is used to manage all Google related products. This does not require a Gmail account. One danger with using Google Gmail with your company email domain is that it locks you into their system. Which means that if you want to move to a new email service, it will be very difficult. It's better to keep it separate and just create a Google Account outside of the email.
To create create only Google Account do the following.
Go to create a Google account