In Sonar each audio track has EQ built in. The idea here is to not duplicate when you don't have to. PT HD has DSP hardware Sonar is native. Its really bad practice to add FX of the same type independently to each track. It takes up unnecessary CPU.
Just a point on that, is that each built in track eq IS a separate instance of a Sonitus eq. As Mike say's you'll often want several track instances of the same plug to control per track setting...no bad practice at all, unless you are duplicating settings on a bunch of tracks, then of course a bus is often the best route. (not always, as something like a compressor even with the same settings will obviously effect say a kick drum on it's own differently to when it's summed with other tracks)
One reason that I'd really want to know what was 'actually' happening 'behind the scenes' in that PT option as it is either setting up several instances or (virtually) bussing the effect ....the only advantage I can see of quickly setting up a bunch of identical instances is if you going to individually tweak them all from the same starting point but seeing as you'd spend time on each individual instance anyway I can't see that ctrl dragging them one by one is much of a penalty.
The other way to acheive the same result when setting up the project is to put the likely fx candidates, sends and such in a single track and clone them then when it comes to it just enable the plugs you want....just a different way of skinning the same cat, as would setting up Track Templates with your usual suspects as far as goto fx are concerned.
These things are often synonymous between two different platforms but the implementaion is sometimes seemingly vastly different.