I'd be wary of the wildcard, especially so given the use of -C on the tar as it will probably be expanded in the home directory of user
before the tar changes directory.
Using '.' will be less prone to errors and will also ensure that you don't miss any hidden files which the wildcard can sometimes miss.
ssh firstname.lastname@example.org ‘tar -C /source/path -cz .' | tar -C /dest/path -xzv