There is a distinct difference yet all too often confusing at times.  Even the most famed wine critics sometimes misinterpret these two.

 Aromas in wine come from 3 different categories:

Primary, which is the varietal aromas (from the grape type itself), secondary, which is the aromas which develop during the pre-fermentation and fermentation process (also called vinous) and finally the tertiary aromas which develop during the post fermentation process and maturing of the wine (in oak and/or bottle aging).

So the primary and secondary types of aromas qualify in the aromas class and the tertiary aromas are the aromas that classify for use as bouquet.

Bouquet is the smell and characteristic of wine, created during the post fermentation process and in the wine bottle itself.  Aldehydes and esters are formed during the oxidation of the fruit acids and alcohol in the bottle.  A bouquet takes time, actually years to develop.  A matured good wine will have a complex bouquet.  I have here listed a few aromas which are only developed during this process.  The following classify as bouquet aromas: prune, mushroom, truffle, cedar*, liquorice*, leather, toast*, roasted almond, roasted hazelnut, caramel, coffee, dark chocolate and smoke* to name a few.  For more information about aromas, please see the works of [1] Jean Lenoir and his must have world renowned [2] Le Nez du Vin kits.

A diligent wine critic will usually not use the word bouquet on young immature wines, unless it is of an exceptional vintage and has already started to show its bouquet prematurely.

 *typical aromas which develop when the wine was aged in new oak barrels prior to bottling.

Cheers!