It is true that the cargo area of the plane is pressurized to the same altitude as the passenger cabin (pets wouldn't survive down there otherwise) but I believe cabins are pressurized to 10,000 ft so there will probably be an even greater area of low pressure outside the bottle as compared to inside than usual. To the extent this provokes explosion is beyond me it all probably has to do with how much you carbonated the beer. I'm wondering though, if the canned beer I usually see on commercial flights is the result of the cans being better able to withstand the pressure than bottles or simply a cost cutting measure? Of course, when those cans are opened the beer doesn't normally come flying out so after thinking (typing) it out, my guess is, so long as you haven't over carbonated the bottle, you should be fine.
Getting the beer through customs? You might have to declare it, but again, I'm not sure?
$.02