Deliberate Bumping is bad Forum practice and is not acceptable on normal threads.
I will never bump a thread.
Having said that it is easy to bump a thread by making an innocent comment, so any objection to bumping is simply peeing into the wind.
The exception are Polls, which must remain near the top of a Loop post list whilst active.
So for all Polls I create, if progressive posts place the Poll too far down the list, I WILL bump them.