Ok. I used my PAL Digital Video Essentials DVD (Chapter 8/11 - Band Limited Pink Noise - LFE).
I set my volume and meter (C/slow) so that (1) below read -10dB.
1) Bitstream decoded in G68 - Discrete: -10dB (G68 LFE display = -10)
2) Bitstream decoded in G68 - Cinema: 0dB (G68 LFE display = +0)
3) Soundtrack decoded in Oppo 980 - Discrete: -10dB (G68 LFE display = -10)
and, wait for it...
4) Soundtrack decoded in Oppo 980 - Cinema: -5dB (G68 LFE display = +0)
So there you have it. Cinema definitely applies a boost vs. discrete. And the result (4) which I double-checked suggests there is a bug somewhere...
For completeness, the test system was 5x DSP33 with *no* sub. In both Music and Movie bass management screens, all five 33s were set to large.