I do (and will always) play Countess G as a woman that is attracted both to men and women since the anime itself don’t show much of her, allowing me to do wathever I want ;P, but...
...maybe she WAS implied to be attracted to women too in the early production of Gankutsuou!
this doesn’t count really much as they both look blushing at Cavalcanti, but now look how she is close to Heloise after here:
and here
I know its very few materials to be considered a proof...
However, first they were both sitting very close to each other in the same couch, where later Heloise try to be close to the count again (another very poor proof ...)
But, all of this a part, the real Countess G (contessa Teresa Guiccioli) was an eccentric, intelligent, acculturated and strong-willed woman; she was almost a rebellion in her time and she was very often not seen as “good woman” by her contemporaries (even by Dumas himself I suspect).
So now, think about a her counterpart in Gankutsuou that do whatever she wants (she is seems without a husband and don’t needs one already) and makes affairs with anybody she likes, even women, I really don’t think that I am exaggerating in my theory seing all in this way.
(Plus if we want to put in there the manga and we think of Heloise as bi XD)
PS: I will forever keep to belive that she had a bigger role in the beginning of the anime production, her design is too much well done!
And Gankutsuou fandom really needs more yuri couples T^T