Well, I got it working. Alan Wake ran. Something about 2 to 3 seconds per frame. Thus, not quite playable.
For future reference (someone correct me if I am wrong but I don't think so):
When you run Winetricks to install Steam you need to exit Steam once it has completed installing. I find it most convenient to login first, take care of Steamguard validation and have it remember my login, etc. Then I exit. After this, you can fire it up again and continue on with what you are doing.
Once you exit Steam, control returns to Winetricks which spawned it and it knows it has completed which then leads to Winetricks exiting.
I think if you run Winetricks to install Steam and leave Steam running indefinitely, you could wait forever for Winetricks to exit because it is waiting for Steam to exit.
This is the sort of stuff that calls for good documentation in the form of a well laid out help system. In this particular case, a message box that can be dismissed after reading this helpful little bit of info would be a good idea. An end user may not think to go looking in the help system at a point like this.
I am basing this on supposition though. I don't recall the behavior when I did this with Wineskin. It is conceivable that Winetricks could download and launch the Steam installer and then exit without waiting for it to complete. Maybe it does? I do know this: when I did this with Barrel I got the same thing. The progress bar indicator (which is non-standard btw - UI no-no). It makes sense to me as normally when you spawn a process in a situation like this, you wait for it to return and then you continue even if it is just to exit yourself.
To offer some more detail on my UI comment just now:
The UI problem with the progress bar in which the bar moves back and forth constantly is that it is a little confusing in the context of a GUI that does not do this as a standard thing to indicate a process is running but it is a process who's progress cannot actually be measured by the section of code in question. There is no way for Barrel or Winetricks to know the progress or even completion of the Steam installation. The best you can do there is put up something to tell the user that something is indeed happening so they are not left wondering if the process failed, crashed, never ran or whatnot.
As I recall, in the Windows world, the SDK provided helpful documentation on user interface conventions. I assume such documentation exists for OS X developers. It would be good to get a hold if this if you don't already have it and consult it whenever the unusual UI situation arises. I don't know if there is an established standard method put forth by Apple for the case where a process who's actual progress cannot be known is running but you want to let the end user know it is in fact running and that all is at least presumably well.
The best thing to do in this situation in my opinion (unless Apple has a published standard to follow) is put up a message box with a generic indicator of progress: a serious of dots or even some other graphic element as desired "for looks" that displays one element or dot at a time in a sequence, is then cleared after drawing x number of "dots" and then repeats itself indefinitely until the running task completes and the messagebox can then be terminated.
The problem I have with the "dancing bar" is that it looks like a standard progress bar but it does not behave like one and is therefore a potential source of confusion to end users which defeats its purpose to inform them that all is well.
I need to stop doing this here me thinks and use github. Sorry about that! I was prompted by what I was reading here, etc. Anyway, I just made an account and will transfer over the substance of this UI feedback there under issues.