My Water is hard water and I have absolutely no problems with any of my fish using it.
Bogwood can alter your tank pH levels & it also releases large amounts of tannin (somewhat yellow in colour),
It will also need to be pre-soaked & to get a log ready can be a long process, like 2 weeks to two-months and theirs no guarantee it will sink then. You may end up having to weight it down.
heres a site with more info on bogwood.
The Use of Bogwood in Aquaria by Majid Ali
Messing with your tank water chemistry is not something that should be done lightly, change one thing it can mess with another and end up with worse problems,
Best way to soften your water I think would be to buy the water and mix it with your own.
But unless your water is really bad or something I'd stick with what brung you,