Other than local.php, I'm not aware of anywhere else you would need to add settings to get this working.
If you're working on the server directly, you might consider moving your auth settings from local.php to
local.protected.php, since that will ensure that only you/someone with server access can modify them, rather than an admin via the web interface. Not directly relevant to your issue, but worth being aware of.
It is certainly worthwhile to verify with colleagues that LDAPS is working for other services talking to this AD server as you suggest. What platform is your web server? Whatever it is, it's also worth getting some LDAP/LDAPS command-line tools on your server and using them to narrow down the issue. Can you query/authenticate LDAPS using a command-line tool on your web server? If not, you'd need to solve that first.