With only 5 months to year end, should I wait to take the 13th month bonus before leaving or switch to a new job with possibility of an increment to monthly salary? What would you do if you were me?

Consider the opportunity cost of the 13th month bonus vs the potential gains after the switch from both a tangible and intangible perspective.

it's a time to be strategic about your next move

Leave for a new job. You can look at it from the perspective that u will be 5 months closer to getting the bonus at your new company.

It depends on on what make u to leave the Jo, if it is for career growth or stress u should leave without waiting . If it is money then u should take the bonus and leave. I left my previous job just one month before bonus, due to politics .

Actually It is 6 months. As you have to serve at least 1 month notice (or 3months in some organisations).