First things First …
The Rewrite Rule
Basically all this rewrite says is (say it out loud) … when I type mysite.com/login
and hit enter, then take the user (rewrite) to mysite.com/wp-login.php
This is not a URL mask or URL Forwarding which is what you are hoping for.
Second Part …
After Login – Redirect too
The url your are seeing contains 2 parts
http://mysite.com/subsite1/wp-login.php
- this is the actual URL for the login page
- as @Brasifilo says you are better of telling your customers to go to
mysite.com/wp-admin
?privacy=1&redirect_to=%2Fsubsite1%2Flogin
- ignore the
?privacy=1
- then
&redirect_to=%2Fsubsite1%2Flogin
is fairly obvious as where to GO after logging in successfully.
- ignore the
Hiding that you’re using WordPress
It’s probably better that your customers know that you have white labelled WordPress … it would give more confidence that their CMS is a trusted open source application used by tens of millions of people around the world. Don’t hide it 🙂