Upon further investigation this is not a bug, but a matter of well concealed settings.
On the other hand, well concealed settings could be considered a design bug.
By default, Nero parses CD Text artist and title from the filename using delimiters (characters such as dashes, commas, quotation marks, etc.). If you go to Audio plugin manager settings in File | Preferences | General | Plugin Lookup | Artist/Title information source and select "Always from the file information block", the will allow the original WAV file name to be used in the audio compilation.
Since a WAV file has no file information block (as does an MP3 file), no artist/title information can be extracted.
The other two choices allow file names to be used for artist/title information, while "Expected filename format" allows the selection of Artist/Title or Title/Artist when it is desired to use the file name with delimiters.
This feature would be very useful in creating CD Text discs when the filenames are arranged by artist/title (or vice versa) with a delimiter separating the categories.