In the position you inquire about, Ian it looks like white has enough for his sac.  We should send the black QR a beer and a snack so he can watch the rest of the game in comfort.  
  I started looking at chessbase online and found no direct match.  The closest I found was a game played in 2000 between GM A. Chernin and GM Van den Doel where black avoids playing Ra7 and most of his problems.  He may even be a little better when they agree to the draw.  Since I don't find the game on chesspub.exe I'll append the score



Chernin,A (2572) - Van den Doel,E (2547) [A29]
Korinthos op 4th Korinthos (5), 25.07.2000

1.c4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.g3 d5 5.cxd5 Nxd5 6.Bg2 Nb6 7.0-0 Be7 8.a3 Be6 9.b4 0-0 10.d3 a5 11.b5 Nd4 12.Rb1 f6 13.Nd2 Bd5 14.Nxd5 Nxd5 15.Bb2 a4 16.Bxd4 exd4 17.Qc2 Nc3 18.Bxb7 Rb8 19.Bf3 Bxa3 20.Ra1 Bb4 21.Nb1 ½-½

They follow your position through White's 18.  Note that black doesn't take Rb1 preferring to grab the a pawn and keep his QR in the action.  I think from black's point of view this is the better way to answer 18.Bxb7. It doesn't seem to have been repeated at the highest levels so I wonder why you refer to it as an "important position"?  Maybe you are referring to the reverse dragon itself?  I know the line is topical through move 16.