I have very fond memories of this museum. However, this trip time will be limited; how long would it take to get there on the bus from the main part of the MET? Is there a better way to get there and what would be the easiest way to get back to Times Square area?

About 45 minutes to an hour.
Easiest? Take a cab back.

It takes about 45 minutes on the A train from Times Square plus the time it takes to board the train and walk 1/2 mile from the 190th Street subway station to the Cloisters.

HTtY

http://www.metmuseum.org/visit/visit...-the-cloisters

By Subway/Bus
Take the A train to 190th Street and exit the station by elevator. Walk north along Margaret Corbin Drive for approximately ten minutes or transfer to the M4 bus and ride north one stop.

If you are coming from the Museum's Main Building, you may also take the M4 bus directly from Madison Avenue/83rd Street to the last stop. (Please allow more time for this option.)

We took the M4 bus. It was a long but fascinating journey, from the coffeehouse featured in Seinfeld to Harlem to Art Deco Dominican neighborhoods.

We took the subway back.