Those aren't faux bold and italic buttons. They're just buttons. If the typeface has the styles, and they are set up in the standard Windows fashion, the links will work fine from using the buttons, and they will get the true styles.
If the fonts are *not* properly style linked as they probably should be, there is nothing the client can do to change that.
If the Bold and Italic fonts show up separately in the font menu in Word, then they're not style linked. If they don't show up separately, then everything is presumably fine.
Cheers,
T