Welcome to GMAT Club! That's a good question.
On one hand, self-improvement and investing in one-self never hurts but besides effort, it also has quite a bit of opportunity cost to get an EMBA and things you will be missing out on and without a clear purpose/goal/application, it may be hard to motivate oneself.
You mentioned you have 2 tracks - promotion within your company or heading to be a CFO of a larger company. I feel an MBA from a top school would be helpful in both situations, as well as provide some protection should the promise of taking over the CEO role not materialize. I don't know if it is worth it though just for that. At the same time, I felt an MBA was a bit life changer for me and for an EMBA, you would build a network with local executives, which would be very helpful if you need to switch jobs.
If you decide to go for it, I would make sure you get a strong brand name.
Good Luck with your decision!