Here's another source that also disambiguates Cantonese from Yue - Cantonese: a comprehensive grammar by Stephen Matthews and Virginia Yip:
 [p. 2] Cantonese is the most widely known and influential variety of Chinese other than Mandarin.  It belongs to the Yue group of dialects.
 [p. 3] Traditionally, the speech of Guangzhou (Canton) is the standard of comparison, hence the terms Cantonese and Gwóngjāu Wá...
It seems to me that although the term "Cantonese" can be used to refer to Yue in general, I have seen no source that does this without needing to preface the fact that they are referring to the more general group.  Every source I've seen always uses "Cantonese" to refer to the prestige/standard dialect whenever the word is unqualified.  This appears to be the common English usage of the word.  —