Does voluntary top up to our CPF MA counts towards reduced income tax? Or does it only count for CPF SA top up?

For CPF MA top-up,

If you are an employee, you can write in to your HR to credit more into your medisave (which also allows them additional 1% tax relief for the company), while you enjoy tax relief from the employment.

If you are a self-employed, yes, you will enjoy reduced income tax (depending on your tax bracket). You must declare your self-employment to CPF too.

CPF SA top up confirm counts towards tax-relief (ceveat, its only reserved for FRS, can't use it for BRS).

Yes, it counts!

From IRAS website: "...Voluntary Medisave (VC-MA) contributions may be claimed as tax reliefs to reduce the amount of tax payable."