Links would be absolute. Use the real safeID of the site.
Your petname system would allow the browser to show the link address using your list. Also the person providing the link in a web page would be using the text field of the link tag. If not then your petname helps out.
So no its universal and globally usable.
Now if anyone uses adblocker they actually have the choice of many adblock lists maintained by different people. So I do not see that a petname system would end up as just one entity maintaining the list everyone uses. For a start different regions would have their base lists.