If you don't have anything to add and can't bounty the question, you shouldn't bump it (though if you can get someone else to bounty it, then in doing so they have bumped it).
However, it's not necessary for your question to be on the front page to be answered. There are many ways questions not on the front page can be answered, and the Community♦ bot automatically bumps questions onto the front page (though there's no guarantee that yours will be bumped).
For a list of reasons/ways that questions that don't appear on the front page still get answered, please see my answer to What to do if your question on AskUbuntu does not get answered?.
One thing you can do, as Call me V mentioned, is to post in chat. However, this is not just useful for finding someone to put a bounty on your question--people in chat may have insights into how you might solve your problem.
When posting in chat, it's best to follow some basic principles of Ask Ubuntu chat etiquette. As I said in that post:
You can ask for help with your question in chat. Just make sure to
stick around, and ask specifically for help, don't just post a link to
your question without saying anything else. And try to avoid asking
for help in chat and then immediately leaving before people have the
chance to reply.