Yes Wine can be used in commercial programs e.g. see Crossover or Google's Picasa for Linux which uses Wine. You have to honor the LGPL license using which Wine is licensed, so if you package your program with a Wine version, you would have to provide the Wine source you used to customers asking for it (just post it along with other open source code used in your program on your website) and mention that parts of the software are licensed using the LGPL in your license. Using Wine code (I mean C-code, so not libraries) in your own program is not possible without making your program itself LGPL.
