The Minecraft website has a feature comparison, and both Mac and iOS are listed as sharing common features, namely 'Realms,' 'player-hosted multiplayer servers,' and 'LAN or WiFi Multiplayer.' The Minecraft page on the App Store for iPhone and iPad also advertises “Play with friends on mobile (and) PC.!” (See screenshots.)
It seems doubtful at this point, but I cannot find a trusted source that says, Yep, it's not possible in any way, so you can stop trying to find a solution. I've been trying in vain to find a definitive answer as to whether there are any options for letting family members use these separate devices to play on common servers or worlds. My family is an Apple household (Macs and iOS devices), and we are getting into Minecraft.
