I think 'linked' is more correct here. As for the difference, consider these examples: a file association is established when files with a certain extension (i.e. txt) are associated with some application (i.e. notepad.exe). Here we would say that text files are associated with notepad. Links establish more firm a connection, i.e. hyperlinks when files are 'physically' or 'logically' linked one to another.
Hmm, does 'publish' fit?