If I create a page rule for a 301 redirect, will that work for one of my Custom Hostnames?

I have a custom hostname for a website I am taking over and I’d like to do a few 301 redirects for their old pages so as not to lose SEO for them. My core domain is also set up using a load balancer, so it looks like this:

Customer website → CNAME to core domain load balancer

If I set up 301 redirects on my core domain, will that property redirect the page from the Custom Hostname that is set up under the core account?