Hi Caserius,
It is fully compatible with BGT and can be installed with or without BGT. Please take a look here for possible installations:
As you see, NeJ3 must be installed on the original ToB game, and VC v2.0 (my compilation) is required.
The supported version of BGT is here:
There is no current support for the beamdog's version of the game ("enhanced" editions). You must have the original game (CDs or GOG version). You may wish to install the widescreen mod to enable high resolutions. I'm playing the game at my 24'' monitor with a high resolution, and it looks great when scaled across the entire screen.
Regarding support in BWS/BWP, the guys here will update you when it is done.
Please let me know if you have more questions.
[EDIT] Just my comment (please don't throw anything at me): The original version of the game is not "out of date" and is not "replaced" with the beamdog's version in any way. It is a marketing policy of beamdogs to advertise everywhere that the original version is outdated and their version replaces the original. In my opinion, these are lies just to increase their sales. The original version is still here and in many aspects is much better than the beamdog's version of the game. If you play at your PC, then you may consider to install both versions and compare them. To fully enjoy the original version, it is better to have the widescreen mod installed to enable high resolutions, as I said above. When I compared both versions, I came to conclusion that the beamdog's version is worse. Again, this is my personal opinion. Of course, if you prefer to play with an Android tablet, then you don't have much choice.
Thank you for clarifying that Vlad, that really sheds some light on things for me. I honestly thought the EE games just replaced the old games, now I know better. Funny enough I'm an old guy, and I still have the original CD's for the entire series, somehow I haven't lost them over these many years. I still have the Versus Walk through guides! Anyway, I will take your advice and install the Original Game, along with BGT and NeJ on my drive that I use for all things Baldur's Gate. And thank you for the links to the additional information I greatly appreciate it.