I guess it all depends on who did the job and how confident you are in thier ability to guess torque settings..
but if you've done the job, then you're the best person to judge when installing things, but if you've left it to someone else it's obviously much harder to judge, if they are an experienced mechanic then it's probably ok.
It's a bit hard to say not having driven your car, but if you have excessive vibration at tickover, or driving along then probably yes, it might need re-doing.
The D/B mount does give a little more vibration than the stock mount cos it's a fair bit stiffer, but if it feels a lot more it probably needs resetting/ torqueing up properly.
When i did mine i didn't torque the centre bolt, but did torque the 4 mounting bolts, and there is minimal vibration once on the move, but there is a litle more than standard or tickover when reving the engine.