Run BindFS after filesystem mounted

Hello,

I use BindFS so that multiple users on my machine can access the same shared folder without permissions issues (I was always surprised it was so difficult, but that's by the by). The guide that essentially sets out what I do is here (Method 1 - Fstab):
https://help.ubuntu.com/community/Bindfs-SharedDirectoryLocalUsers

I have recently rebuilt my machine and now I want the shared directory (/home/shared) to actually be on the spinning disk rather than the SSD. I can do this with:
bindfs -o perms=0700,mirror-only=aaron:user2 /media/spinning/shared /home/shared

If I put this into my /etc/fstab, however, it sometimes works and sometimes doesn't, so I suspect it is to do with whether /media/spinning is mounted before it tries to do the BindFS mount. I therefore want to run the command after the filesystem is mounted. The guide linked to above sets out how to do this as Method 2, but only using an Upstart job.

I tried to convert this to a systemd job, but it doesn't seem to be working:
/etc/systemd/system/mountbindfs.service
===
[Unit]
Description=Run BindFS so that both users can access folder
Requires=media-spinning.mount
After=media-spinning.mount

[Service]
Type=oneshot
ExecStart=/usr/bin/bindfs -o perms=0700,mirror-only=aaron:user2 /media/spinning/shared /home/shared

[Install]
WantedBy=multi-user.target
===

Can anybody suggest what I've done wrong?

Thanks!