I wouldn't. Asking someone else to give up a large sum of reputation seems a little pushy to me, and even though I'm sure some users would be more than happy to, I suspect most would find it a little rude.
But that said, I know it's frustrating to need an answer and not be able to get it.
There's another question, What should I do when a user stops responding to me in comment?, which has a few answers that discuss alternatives to bounty placement, including asking for help in a chat room. That's probably not a bad place to start. I would start off there with asking whether it's appropriate to ask for help on a question in there, but I suspect as long as you're polite, nobody will take issue.
You might also be able to ask more broadly in a chat room how to bring more attention to the answer without a bounty. Some sites look at that differently, and users in the room will likely know their sites culture pretty well.
Another solution might be just working to get the reputation yourself. There are lots of ways to gain reputation, the easiest (not to understate the importance, of course) of which being to make suggested edits. If you can clean up some questions and answers, you can get enough rep to post a bounty of your own. Obviously, also, you can check around for unanswered questions that you can help with.
I haven't looked at the question you linked to yet, but in some cases, you may find that there's enough worth editing on it that it'll get bumped to the front page, and that might get it an answer indirectly. That shouldn't be relied upon, and definitely don't make edits with that goal in mind, but it could be a nice plus if you, again, can find enough problems to make it worth editing substantially. That'll also have the advantage of making potential answerers more keen to help.