In February we hope to fly from Paris to visit Prague but find that the airfares to Bratislava are so much less expensive than to Prague. Would it be feasible to fly into Bratislava and then take shuttle bus or train to Prague?

4 direct day-trains, taking just over 4 hours from Bratislava to Prague, each day. Plus some sleepers. And you need to take bus or taxi from airport to train station. It becomes a whole day trip from Paris.

I don't know the airline personally, but I'm seeing weekday/February Paris (CDG) to Prague flights on SmartWings for about 68Euro, including tax. Just in case you hadn't come across the option.

I'm not seeing flights listed any cheaper than that to Bratislava.

http://www.smartwings.net/en/

I travelled on SkyEurope a few years ago from Bratislava to Paris and back again (before heading to Vienna). At that time SkyEurope left from Orly Airport. Once you get into Bratislava you can take a cab to the train station and a train to Prague. It is very easy. The airport in Bratislava is very small and the ride to the train station is fairly close. Just an FYI- Bratislava is closer to Vienna and SkyEurope runs a shuttle bus service into Vienna. It must be booked in advance.