This is an error not specific to Tale of Two Wastelands, but solid information on it was sparse and inconsistent on a Google search. This is the solution I came up with to fix it and I'm sharing in the hopes it will help others who come across it.
The error:
On launch the game crashes to desktop and provides a rather unhelpful error message box stating "Failed to build Gamebryo renderer" (paraphrased, because I didn't think to take a screenshot for future reference). This message will occur no matter the launcher you use, be it a mod manager, steam, the .exe's directly, etc. It effects both Fallout New Vegas and Fallout 3. Ostensibly it effects Skyrim as well, but I didn't check.
The message is slightly different when launching Fallout 3 and is slightly more helpful, referencing an incompatible screen resolution (again, paraphrasing).
Somehow, the video settings have gotten messed up in such away that even resetting .ini's and configs won't help. I tried deleting .ini's and configs, and verifying integrity through steam. The video settings menu, accessed through the vanilla game launcher, only listed a limited set of options. In my case, it was only giving me 16:10 aspect ratio options when my monitor is 16:9.
The fix:
Disable and then re-enable your video card drivers (explained in further detail below) and then manually set your video options to the proper aspect ratio and resolution through the vanilla launcher.
First open your Device Manager, this varies based on Windows version, but generally you can right-click on My Computer on your desktop and select Properties and the device manager should be available from there.
Within the Device Manager, expand the Display adapters and right-click on your video card listed there, and again select Properties.
In your video card properties window select the Driver tab and click the button labeled Disable. You may get a confirmation screen, select OK. This will disable your video card driver.
Your screen will go blank and after several seconds come back up with very low settings. This is Windows falling back to a generic, wide compatibility video driver. You may have to reposition things to see all the appropriate buttons.
What was the Disable button will now show as Enable. Click the Enable button to turn your video card drivers back on. Again your screen should go blank for several seconds and come back up with your previous full resolution desktop.
Close out your device manager windows, start the vanilla FO3/FONV game launchers and make sure your video settings are set appropriately and you're done!