Lycanthrope

Just add the additional domain & ip like so:
RewriteEngine On
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?domain.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://xx.xx.xx.xx.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://xx.xx.xx.xx:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?otherdomain.com.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://(www\.)?otherdomain.com:80.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://xx.xx.xx.xx.*$ [NC]
RewriteCond %{HTTP_REFERER} !^http://xx.xx.xx.xx:80.*$ [NC]
RewriteRule .*[Jj][Pp][Gg]$|.*[Jj][Pp][Ee][Gg]$|.*[Gg][Ii][Ff]$ http://redir.url [R,L]

__________________