I am running the trainer for v1.02 on the Steam version of AT2 without issue. At least without issues related to the trainer. My computer is running Windows 7 R1 x64 on dualcore 2.8Ghz with 6GB RAM and NVIDIA GeForce GTS250 3MB RAM with DirectX v11. When I first installed I had issues with game crashes both with and without the trainer so I don't believe it was trainer related. I went to the NVIDIA site to check for upgraded video drivers and installed them. I also lowered the video resolution in the game from high to medium yesterday. I played a few hours last night with the trainer on and I used it (Like the cash) without issue.
FYI: Someone on the AT2 website recommended running the game with Administrator priv to resolve the crash issue on x64 systems. This does not work with the Steam version as you can modify the game properties directly you have to apply the compatibility change to Steam. I tried it and Steam crashed with all new errors....so I do not recommend that solution.
PS and the Trainer for Empire Total Work definately works with Steam - that was the game that installed Steam on my system and I've been using it happily for a long time.