How to prevent ReweiteRules to match subdomains - apache

Question

How can I limit my mod_rewrite RewriteRules to only apply to the www and no-subdomain?
The subdomains are in different folders -- rather website root folder, however all of my RewirteRules apply to all of the subdomains, which is not what I want.
I know that it's possible to match every RewriteRule by a RewriteCond that only matches www and no-subdomain, but then I have to repeat the same thing for all the RewriteRules, which is not what I want again.
So I was wondering if there is any way to globally prevent RewriteRules to apply to other subdomains? I can also place .htaccess files in each subdomain as well to prevent matching, if that's a possibility.
Here is part of what I have in .htaccess right now:
options -Indexes -MultiViews +FollowSymLinks
Header set Access-Control-Allow-Origin *
RewriteEngine On
RewriteBase /
RewriteRule ^city/([^/].+)/([^/].+)/([^/].+)/$ index.php?page=$3&city=$1 [L]
RewriteRule ^city/([^/].+)/([^/].+)/$ index.php?city=$1 [L]
RewriteRule ^flights/([^/].+)/$ index.php?page=flights&mode=$1 [L]
RewriteRule ^health/([^/].+)/$ index.php?page=health&view=$1 [L]
# so on ...
RewriteRule ^([^/].+)/$ index.php?page=$1 [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-l
RewriteRule . index.php [L]
Update #1
Just to explain the problem better, right now sub.domain.com shows domain.com instead of it's actual content.

Answer 1

You can insert this single rule below RewriteBase line to ignore all sub-domains from rest of the rules:
# ignore all sub domains
RewriteCond %{HTTP_HOST} !^(www\.)?example\.com$ [NC]
RewriteRule ^ - [L]
Replace example.com with your actual domain.