I had a similar problem just the day before (Photoshop could not see fonts in drive_c:\windows\fonts), but I found a workaround:
Step 1: check your registry
+ Open playonlinux, click Configure, choose the virtual drive you installed illustrator in, choose Wine tab, click Registry Editor
+ Go to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Fonts
(This is where the installed fonts (from the view point of the virtual drive) are listed. If a font is not registered in here, wine programs can't see or use it)
+ Check whether the fonts you installed are listed in here. If they're not, chances are wine does not scan the 3 directories you mentioned for fonts, and in which case you have to manually register those fonts, which lead us to Step 2. (If, however, the fonts ARE listed, then they have definitely been "installed". And if illustrator can't see them, I'm not entirely sure but I guess the blame goes to illustrator, not wine or pol)
Step 2: Manually add custom fonts
+ Option 1: You can...technically add a new string value for each font you want to install (but I bet no one wants to do this)
+ Option 2: Use a font installer. I recommend NexusFont - this program is actually a font manager but it can be used to install fonts as well (and it's ridicuously light - 2MB for setup file & 8MB for installation). Here is how you could proceed:
--Install nexusfont to the SAME virtual drive as illustrator
--Open it, in the left pane right-click on "Sample Folder Group", choose Add folder, browse to the folder you put your fonts in
--That folder'll be added below "Sample Folder Group" (you may have to expand "Sample Folder Group" to see it), click on it and the fonts in it will be loaded in the right pane
--In the right pane, select the fonts you want to install (or select all by Edit > Select All), right-click, choose Install (or Alt + I, or File > Install)
--The Install dialog appears, choose option 2 - "Leave files where they are" and click Install. IMPORTANT: do not choose option 1 - "Copy files to the system fonts folder" as it will only copy fonts to drive_c:\windows\Fonts WITHOUT registering them to the registry (on windows, when copying fonts to this folder, explorer automatically adds them to the registry, but apparently wine does not)
--Restart illustrator
That's it! Now your fonts should be visible to illustrator. Using this method, you can put your fonts in whatever folder you want. You don't even have to install them as system fonts (and potentially drag down your system's performance with hundreds of fonts). Just link the folder(s) to nexusfont and install them even selectively as you wish.
Hope this'll help.
Editado por: the_n