I'm reading Hsu's Rise of Modern China right now, and I'm investigating the Taiping Rebellion for funsies (I feel like the world's dullest person, but hey). Compared to the government's nepotism, corruption, and general inability to deal with both the distribution of land and the natural disasters that had been destroying China in the last couple of years, Hong seemed to be a perfect alternative.
However, when I read into his policies, some of those being the equal distribution of land and wealth amongst peasants, I can't help feeling that some of these policies are very... Marxist. Could he be described as a modern day communist? Was there any connection between him and Marx at all?
I think you need to tread lightly in applying labels in such a way. It's the argument of if Jesus in the Bible was a Socialist. While that's all well and good for people trying to push social agendas, it doesn't have much place in an historical analysis. The best you could do is to point out similarities between what Hong taught and the ideals of Marx, but unless you know for sure that Hong was aware of Marx's writings and incorporated them in his own situation you can't really call him a Marxist.
I'm leaving the whole "what is Communism" fiasco out of this, as you probably noticed.
edit: (now that I understand the question better)
Marx certainly knew of the Taiping Rebellion and wrote on the topic in 1853 – first in support of the Rebellion as a class strugle that was the result of English meddling – and later in 1862, having changed his opinion and now considering them to be "devils".
However as far as I know Hong did not know of Marx or his writing. His history is of someone who failed the civil service exam and was then introduced to the Christian Bible, and not someone who was otherwise well read on the subject of class struggle.
Stephen Platt's 2012 book Autumn in the Heavenly Kingdom certainly makes no mention of Hong being aware of Marx anywhere in its 460 pages, and it's not something i've otherwise ever encountered. So unless someone's come across something to the contrary, I think it's safe to say Hong was not aware of Marx's ideals.