Yes, there are separate circuits for both front and rear ABS, and they work independently from each other. You can test it by just standing on your rear brake when going 20 MPH or so, you'll feel the ABS kick it on the rear. You can do that on the front as well, but if you crash don't blame me! ha ha!
Well, I've felt ABS activation from the front (really odd, never had an ABS bike before). I'll check out the rear next time I get a chance. I usually avoid the rear brake completely unless I'm in loose dirt, stuff like that. I really only use the rear when I'm on a hill stopped in traffic. I had some scary moments with the rear locking up on my old Honda, and eventually I just stopped using it all together. I guess with ABS, I could start again without the same issue. And if it all goes horribly wrong, I won't blame you, lol