will be helpful for those in need They are not necessary for mod_rewrite, as unknown directives are not interpreted, so it is more or less a style thing. The tag can also used to perform test for not available modules with , so that you can use some other directives in that case.
mod_rewrite point subdomain to subfolder (which contains more mod_rewrite rules)
I wish did fix the issue. It looks like (at least on 2.4.6) that RewriteOptions inherit helps, placed either in httpd.conf or .htaccess. According to docs, this should only force VirtualHost to inherit rules from main server configuration, or in per-directory context to inherit parent directory's .htaccess configuration, but I tested and it seems to resolve your issue.
Mod_rewrite and URL redirection - APACHE,Mod_rewrite,PHP,Codeigniter