Steps to reproduce:
1. log in to a gnome+wayland session
2. open gnome-control-center
3. change some key binding or add a new one
4. set the key binding to e.g. <Super>+<T> or <Super>+<Alt>+<T>

What happens:
If you are just setting it to <Super>+<T> (or any other "normal" key instead of "T") you will see a message that setting key bindings to "T" is not allowed since it would be unable to type with.
If you are setting it to e.g. <Super>+<Alt>+<T>, it will be displayed and configured as if you were just typing <Alt>+<T>.

This issue is not present on gnome+X11 sessions. Setting a key binding in a Gnome+X11 session using gnome-control-center makes the key binding work fine in Gnome+Wayland sessions too. You can also set it using dconf-editor (on both kinds of sessions).

Software versions:
gtk3-3.18.2-1.fc23.x86_64
control-center-3.18.1-1.fc23.x86_64
gnome-shell-3.18.1-1.fc23.x86_64
mutter-3.18.1-4.fc23.x86_64
clutter-1.24.2-1.fc23.x86_64