I like Earl Grey tea very much, and recently came across Earl Grey tea from the East India Company. The East India Company is famous for its trading, political, and military activities in the 17th to 19th centuries, but I hadn't realised it still existed, so I bought the tea with interest. I later found out that the makers of this tea are actually a company founded in 1987, with no link to the original East India Company. But that doesn't matter because the tea was great!
Most Earl Grey tea gets its distinctive flavour from bergamot oil. According to the company's research, however, that oil wasn't known in the early days of Earl Grey tea, and they suggest that neroli oil (oil from the flowers of the bitter orange tree) is likely to have been the original flavouring, so that's what they now use in an attempt to recreate the original tea.
It looks like the best place to find out about different kinds of Earl Grey tea is the Tending Towards Tea site.