Just got this working and thought I'd share.

Mac OS 10.7.5
Engine: WS9 Wine 1.7.10
Wrapper: Wineskin 2.5.12

Download the setup.exe from GOG.
Make a Wineskin wrapper (I use Wineskin Winery).
Click on the wrapper, choose Install Software.
Navigate to the setup.exe, install.
Click Exit instead of launch.

All the standard stuff, unfortunately that then leads to screen tearing, video stuttering, and blackness instead of fun game times. Sooo, on to the fixes!

On your wrapper, show package contents.
Click the Wineskin.app inside.
Click Advanced.
For the .exe browse to GOG Games/Age of Wonders Shadow Magic/AoWSMSetup.exe.
Test Run it. Set the resolution to your screen resolution, for instance 1920x1080.
Set the Cursor to Black and White. [This one stupid little thing fixed so much lag it wasn't even funny.]
Quit out of the AoWSMSetup.exe
Browse back to GOG Games/Age of Wonders - Shadow Magic/AoWSM.exe (in the Windows .exe box).
Now then, choose Set Screen Options.
Override to a Fullscreen, Current Resolution (this MUST match the resolution chosen in the AoWSMSetup.exe), Force normal windows.
Click Done.
Now, go to Tools.
Choose Winetricks.
Under Settings, check the box for ddr=gdi. Click Run.
After it finishes, close it, and close the wineskin advanced panel.

Ta da! Age of Wonders Shadow Magic now runs without tearing or cursor lag! \o/ I haven't run into any problems yet but I'll do more thorough "testing" tomorrow. :D

I do know PaultheTall has a wrapper up, and if that one works for you great! Unfortunately, the top fifth of my screen was tearing like mad and so I just decided to give it a whack from a blank slate. Very happy with it so far. Have not attempted multiplayer yet.

Ack, guess I jumped the gun in proclaiming success. Scrolling around the map is sticking. Back to tweaking I go.

I have at least found out how to get the movies to play: Find "dpnet.dll" on the internet and drop it into the same folder as AoW2.exe (drive_c -> GOG Games ->...)

My biggest problem is the screen flickering in full screen; running ddr=gdi fixes the flickering, but it tanks my performance at lot. From what I was able to see performance was excellent in fullscreen when using OpenGL as my Direct Draw Renderer.

EDIT:
Check this out: two flicker-fixed Wineskin engines
https://github.com/lnxbil/WineskinEngines

The patches take care of the flickering in fullscreen, and while performance is still not up to Windows it is at least playable even at 1980x1200 in fullscreen. Make sure to turn on the Mac drive in Wineskin's screen settings.

Nice! That actually also solves a problem I was having with another game. By the way, if you have CrossOver, AoW Shadow Magic will play in CrossOver 13.0 in a Win7 bottle, fullscreen, without any performance problems that I've seen. However you have to make a separate run command go to the .exe since it wants to open the .lnk, I have no idea why.

Hmmm, I'm getting slightly lower performance than in Wineskin, but that may be due to my hardware. Ich have an early 2009 iMac with an Nvidia 9400M and an Intel Core2Duo 2.66 GHz. It's interesting that Crossover have fixed the flickering bug, I didn't know that. I wonder if the lower performance is because of that fix though, I know the flickering was cause by some optimization in Apple's OpenGL.