The TT is built on the Golf/A3 platform, so uses a transverse engine.
I THINK the problem is the flange on the exhaust manifold is slightly different, the gasket is certainly a different part number, which might suggest its a bit larger.
Its one of those things, any time it comes up people say "it doesnt work" but i dunno just how hard someone has actually tried to fit it, or wether they've just taken one look and ran away because it doesnt quite fit properly.
You might be able to use the entire TT manifold. It wiull move the position of the turbo but it might still work, would just require some pipework moved assuming it physically fits in the engine bay.