Unfortunately the Amiga version was never released. You can however easily play the Mac version of the game on your accelerated A1200s using Shapeshifter!
I couldn't find a working copy of the game myself, so I didn't add it to the MacGames HDF I made, but you can still download both that and the MacOS (7.6.1) HDFs from the EAB File Server, install Shapeshifter, then just make some room on the MacGames partition by deleting a game you don't want and replacing it with The Settlers II if you can find the Mac version somewhere.
If you haven't set Shapeshifter up before or try setting it up and have some problems, let me know and I'll try to help. I wrote a post a little while ago with some basics of what you need to get it all working -
http://eab.abime.net/showpost.php?p=712359&postcount=53
Give it a try if you're curious, I'd love to see the results (since I can't find a working copy of Settlers II for Mac to test myself
)