Its a grey area of course. Sharing it as download isnt allowed by default. But I think its accepted as long as you follow some basic guidelines.
First things first: you can share a stream of your bootleg (Youtube, Soundcloud). If you are looking for feedback on your production, get tips on how to improve, some selfpromotion, then the Music Production area is the place to be.
If the bootleg has a more professional approach, it’s a quality-production, perhaps played by dj’s, you’re planning to release it as a ‘freebie’, then the upcoming release section can also be appropriate.
When you do that (release as freebie), make sure to credit original producers, expain yours is unofficial, and provide links to purchase the original tracks. That way, most labels wont demand a removal, as it is fair promotion