Code
# include ALL required code including stylesheets and base64 encoded images within bounce.php as external links are not allowed for the visitors who will see the bounce message
RewriteRule ^bounce/?$ /bounce.php [L,END]
# include the ISO3166 codes of the countries you want to *allow* access in the list
RewriteCond %{ENV:GEOIP_COUNTRY_CODE} !^(US|CA)$
RewriteRule ^(.*)$ /bounce/ [L]