I think the buddha said the past is gone and the future yet to be, and not to cling to the present!
Let me have a go at trying to sift this out for you:
Lets assume that we have a very messy room- so messy that you cannot see the floor. Now the top most layer of stuff is clothes. That layer completly covers the layer of toys underneath it- unless you clear some of the clothes away. Underneath the layer to toys is a layer of books, which in turn completly covers the floorboards ... lets just say shall we!?
In this analogy the topmost layer is sankhara/mental fabrications.
The layer underneath is sanna/identification
The layer beneath that is vedana/'feelings'
and beneath that is phassa/contact.
Even further beneath that is the arising of vinnana/consciousness and below that is the the sense base and stimuli
Now to get to the bare wood, we need to clear all the top layers...right?
Well to do that we use a strong/intense mindfulness which has a lot of samadhi in it. As far as the room analogy goes you can think of something which emits a very strong blast of air (hmm maybe a gardening analogy might have been better -too late!-so that it clears layer upon layer of stuff so that we can get to the bottom.
WE often hear the terms- 'dont be attached, dont have aversion, just watch with equanimity'- this is simply getting rid of the sankhara layer which contains attachments and aversion. It is possible to get to deeper and deeper layers as mindfulness and samadhi (concentration) grows over progressively longer periods (ie longer retreats).
I think 'bare awareness' is simply being mindful without any mental chatter ( once again -sankhra level) or perhaps even without sanna/idenitification ('just the seeing in the seeing....'). What I would say is that to get to the bare floor boards a yogi would need much more than just mindfulness. He would need samadhi-concentration-unification- which would really penetrate deeply into the phenomena at hand- like a surgeon's scalpel piercing through. Mindfulness in that scenario would be like the giant surgical theatre lights which light up everything but doesn't penetrate underneath the skin.
Ven Bikkhu Bodhi is interestingly barking up a different tree -perhaps taking the opportunity to say his bit (even though he is making a valid point - one which the neo-vipassakas would do well to listen to..)
In any case, hope that is helpful,