I know it's a limitation of the english language, depends on what you call which. If you call linked to either source or destination provided that both exist, then yes both are "linked" to each other. But I think this only adds confusion.

I would keep "linking" or "link" for source or linkname,
and "linked" for destination or target, as ln does:

ln [option]… [-T] target linkname

Let's create a simple archive:

$ echo "foo bar" > myfile
$ echo "team" > myfile2
$ ln -s myfile mylink
$ ln -s myfile mylink2
$ ln -s myfile2 mylink3
$ tar -cf archive.tar myfile myfile2 mylink mylink2 mylink3

As a general rule in english, verb + ing is for active when referring to a subject, while verb + ed is for passive, so I would use "linking" or "link" for active files or members (links), where you can perform some action:

• ‘--hard-dereference’
• ‘--keep-directory-symlink’
• 'symlink-cast'
• ‘--overwrite’
• ‘--dereference’

Also this is the way it's described in the manual, as link not linking:

hrw-r--r-- gray/staff        0 2006-06-09 12:06 music link to blues

As a part of being active, with a simple "tar -tv" you can know to which member they point without any further investigation (they are active and tell you right away):

$ tar -tvf archive.tar mylink
lrwxr-xr-x nb/staff        0 2022-12-30 00:00 mylink -> myfile
$ tar -tvf archive.tar mylink2
lrwxr-xr-x nb/staff        0 2022-12-30 00:00 mylink2 -> myfile

However, listing a linked member doesn't tell anything about which (if) links or linked members point to it:

$ tar -tvf archive.tar myfile
-rw-r--r-- nb/staff        8 2022-12-30 00:01 myfile

Even there's no tar option to tell which (if) link(s) point to a given member:

$ tar --check-links -tvf archive.tar myfile
-rw-r--r-- nb/staff        8 2022-12-30 00:01 myfile

It has to be one with other command than tar:

$ tar -tvf archive.tar | grep ' -> myfile$'
lrwxr-xr-x nb/staff        0 2022-12-30 00:00 mylink -> myfile
lrwxr-xr-x nb/staff        0 2022-12-30 00:00 mylink2 -> myfile

Maybe you don't agree with me on this, but being used to reading lots of documentation this seems incongruent right away.

The line
"The size field is the size of the file in bytes; linked files are archived with this field specified as zero."

"linked" should be changed to "linking" or "link".