Hello:
Are you and your friends from the same listening region? If you are you should see the same content available as well, unless your friends are using a method not approved or condoned by Spotify's ToS to access content from different listening regions?
I looked up that content, used Google to find the Spotify album links you might have been posting about. I am in the States, so that content as well is not available to me from both artists. E.P.'s and Bonus content on albums are hit and miss by artists sometimes. And with labels releasing multiple versions of the same releases to capitalize on the different music delivery methods between streaming, digital, and retail traditional CD and Vinyl, speciality retail chain releases, e.g. Best Buy, Target, Walmart with different bonus tracks offered on different releases, the whole release schedule can get even more confusing with bonus released tracks from labels.
Spotify wants all the world's music, and they're working hard on making this happen for you. However sometimes agreements can’t be reached with the artist or label or a change may happen in music ownership.
Spotify adds thousands of albums and artists are added every day. If you can’t find an artist you’re looking for, they may appear (or reappear) soon. In the meantime, feel free to contact the artist or their label to ask when they plan to be on Spotify.
https://support.spotify.com/article/Content-missing/
Spotify users can use this Google form here:
https://docs.google.com/forms/d/e/1FAIpQLScMGwTBnCz8nOPkM5g9IwwbpKolEWOXkhpAUSl8JjlkKcBGKw/viewform for music requests, there is no guarantees the content added to this list will become available. This is an internal list Spotify uses internally to see how popular certain content is that might be missing on the service.