Second domain, one wordpress account?

Hi there,
I currently have one blog using ww.wp.xz.cn. I registered a second domain and am wondering if I can use my same WP.org account for both, or will I need to set up a whole different WP.org account for the second domain (this domain will have nothing to do with my first site – both domains are through HostGator.com).

Thank you!
Miranda