This is the exact same interview that can be found on the box set, Kate Bush On Compact Disc, which you can find right here. This interview can also be found on several other discs, and none of them are official releases. It runs about seven minutes in length, and even though the interview is alright, I do have a couple of problems with it.
The actual recording is running slightly too slow at times, and the sound is slightly muffled as well. These problems are also evident on the CD version 'Kate Bush On Compact Disc'. Although I haven't listened to this one in a long time, I believe this was taken from the official Canadian promo LP 'An Interview with Kate Bush'. The material from the official Canadian promo turns up on a lot of these unofficial releases. The interviewer is fake and Kate's responses were pre-recorded alone.
If you're into collecting interview discs, I would suggest picking up this 7" version as opposed to the CD version. I have seen the CD box set version go for stupid amounts of money and it's hardly worth it. It's the exact same interview, and you will definitely get the 7" picture disc for much cheaper.