I was going to buy this movie years ago, but was waiting for a good price on the blu ray version. But now that you mention there's a 3D version...
The concern is, the movie didn't do that well in theaters, barely breaking it's budget. It needs to earn twice the amount to break even if theaters get half of the box office. If a movie's a hit, it tends to be more willing to release special editions/versions/3D.
The Ant Bully
Domestic Total Gross: $28,142,535
Distributor: Warner Bros. Release Date: July 28, 2006
Genre: Animation Runtime: 1 hrs. 22 min.
MPAA Rating: PG
Production Budget: $50 million
Total Lifetime Grosses
Domestic: $28,142,535 51.0%
+ Foreign: $27,038,594 49.0%
= Worldwide: $55,181,129
But seeing Warner Bros is behind it, there's a chance they'll be open minded and give the 3D a go on blu ray 3D if it was available in 3D at one time.
http://www.boxofficemojo.com/movies/?id=antbully.htm
I checked boxofficemojo, which usually lists a 3D section for movies, but didn't see one for Ant Bully. I did do a search for it and it brought up one image sample of Ant Bully Imax 3D, but didn't find the article reference to the 3D anywhere.
That link gives some proof it was in 3D way back in 2006, the same year Open Season 3D hit theaters (and looks awesome in strong 3D). Hopefully Ant Bully has the same strong 3D, having not been softened by the trend to make 3D mild as we've seen Pixar do for so long until Good Dinosaur.