I know Speech doesn't exist under System in Mono because Mono lacks SAPI, but the same error occurs when using the .NET Framework (4.0) with Wine.
Is there a way around this? (I hoped I was being clever. :/)
For reference, my Dockerfile: https://github.com/stephenwithav/docker-wine/blob/master/Dockerfile
Example speech code for testing: https://msdn.microsoft.com/en-us/library/system.speech.synthesis.speechsynthesizer.setoutputtowavestream(v=vs.100).aspx