This was changed very recently in Wine, it used to not show, but then they changed it to force it to always show no matter what... I think it did that for all Wine versions, so your Ubuntu test might have been an older Wine version. I find it highly annoying myself that it cannot be disabled... but I have it running in a way it doesn't matter with Wineskin. If you use Wineskin and set the screen options to Override->Fullscreen, it runs X in fullscreen mode, but Wine in a virtual desktop, and Wineskin monitors the Wine log and changes resolutions for you when its asked, so it works like normal full screen for the most part, but Wine is in a virtual desktop. To get around the quartz-wm decoration always at top, you'd think you could just turn off the decoration, but no.... XQuartz always leaves space for quartz-wm title bar if quartz-wm was started, so you get the whole picture pushed down the screen 22 pixels just like the top bar is there. I have to make Wineskin never start up quartz-wm if your doing the override->fullscreen option so everything draws right... and since there is no window manager running, Wine can try to force that decoration on, but nothing happens... The only way I've found to do this in XQuartz is to start XQuartz directly by running the Xquartz.app/Contents/MacOS/X11.bin executable in the command line, giving it a display number... like... /Applications/Utilities/Xquartz.app/Contents/MacOS/X11.bin :55 Then you'll get it to start up with no window decoration present and if you run something in Wine in a virtual desktop, you'll get no window decoration.
