This has been a question I've had for years, but I've come to the conclusion that the answer is "no", it seems a PTR record can only map back to a single host.
If you're in the webhosting business, your usual reason for wanting to do this is because you are setting the primary MX record of the domain in question (eg. mydomain.com) to mail.mydomain.com which often makes migrating it easier later. Unless you have lots of IP addresses to spare, you are generally going to be stuck with a single IP address for your mailserver, and for a mailserver it's really important that reverse and forward DNS match. I just set up the Reverse DNS to something specific to my business, eg. mail.businessname.com, make sure the PTR record for it's IP matches that, and set that as the primary MX for all your domains.
One last thing though, the example you quoted is on a private subnet, so you possibly have lots of IPs to play with, so you could perhaps add some extra IPs and have them reverse map properly. But I suspect it's WAN IPs that count here!