Over in the USA, Lindasusan has a nice little idea about "non-donation" cheques to send in to the fundraising arms of LGb organisations when they do pieces of work that marginalise bi experience.
Now, at an instinctive level, I like this. So long as bis are an invisible and silent group, we will never be seen as an activist pool / funding opportunity that is being passed up. A little pile of "I'd've sent you a tenner, you know" speaks volumes.
But I think I'd like it more if there were followup "here is a donation following your better work" alternatives, or even "I have donated €.... to bi organisation ____, it would have gone to you guys if I didn't feel so left out by your work." The latter especially: for most of us it's a whole heap easier to say you would have donated to something than to actually do it, so actively donating to BiPhoria or BCN or what have you is a much bigger statement.