In the Jesus Seminar (conducted 1985-1993) and the Acts Seminar (2001-2011), both conducted by the Westar Institute, scholars voted on the historicity of various passages using color-coded beads. That's come under criticism by N.T. Wright and others. The Wikipedia article says, "The concept of voting on aspects of early Christian life and the accuracy of biblical sayings was not a unique innovation of Westar. Rather, it was based on 'the disciplined work of Bible translation committees, a very traditional scholarly practice,'" quoting a book I don't have access to. Is that aspect of their methodology generally considered sound? And is it indeed as widespread as the article makes it out to be?
I guess you would have to explain what you mean by "reliable." The Jesus Seminar was essentially a survey, not an attempt to close conversations or decide on definitive conclusions. It is "reliable" in the sense that is an accurate survey of the views of the scholars involved. A majority view is simply a majority view. There is nothing illegitimate about taking a survey of scholarly views. Scholars with primarily apologetic concerns like Wright might not like the results of those surveys or not like for the public to know what critical scholars really think, but that doesn't make a majority view he doesn't like cease to be a majority view. It also doesn't mean the majority view has to be correct. There were fellows within the Jesus Seminar who voted against the majority view on many questions and those votes are noted. All they were really trying to do was compare notes and find out what they agreed on, they were not trying to say "this is fact."
Bible translation committees pretty much have to vote because they have to make a final decision on how to translate something.