Sorry, did I hear you correctly? "Cheating" in the workplace? I'm not sure there's any such thing is there, unless of course there are rules in your company about using your initiative to be more productive, in which case I'd look for another job!
I'm sorry, this answer is quite opinionated but I say keep it up! Your employer is obviously recognising that you're being more productive from the fact you've got the bonuses so why should they discipline or fire you? On saying this however, I agree with some of the posters above that publicising who has "won" the bonus has the potential to cause friction amongst colleagues, so maybe publicising it isn't the way forward.
Sounds to me like some of your colleagues are more than a bit jealous they haven't thought of these ideas themselves and got the weekly bonus or are simply too afraid of change and cower in the face of progress. Smart people would learn from your example and seek to optimise their own workflows by adopting similar techniques but as you have already tried to share your knowledge and been rebuffed, the people accusing you of (sorry, I have to laugh heartily here...) "cheating at work", should pipe down back there in the dark ages.
I would never even entertain the idea of accusing someone of cheating at work because they're being more productive than me and being rewarded for it. That would be a spiteful (and quite pitiful) act on my part.