First of all welcome to the forums!
Your bengal breeder should be best to advise you on wether your cat is or is not show quality......You can show any cat though provided it is registered with the appropriate governing body (i.e GCCF, TICA or FIFE if your in the uk). This will depend on the individual show and which organisation it affiliates itself to!
Normally quality show/breed Bengals will be sold at a much higher premium than a pet quality one and should be registered on the active list (this also entitles you to breed from it).....The
only difference is that the pet bengal will be on the non-active list and may have a couple of minor traits such as maybe a tiny white locket of fur on the breast or a slight kink in the tail etc.....hardly noticable to your average pet owner
The show/breed bengal on the other hand will be almost perfect and will certainly carry something that a future blood-line would benefit from (i.e whitened tummies, rosettes, glittering etc).
Anyways if your not still in touch with your breeder.....just check your bengal against the SBT (breed standard).....That should give you a good clue to the quality of your cat and most importantly if it stands any chance of winning!
I'm not sure what country your from but thats how it is in the uk.....Hope this helps