ROMM is defined as “The risk that the financial statements are misstated PRIOR to audit.” Thus it is made up of the two components inherent risk and control risk.
Matters to consider is just that … what is it that you should be thinking about? It depends on context – so risk (IR and CR) is a matter to consider in planning audit procedures – but so too is materiality, whether you are seeking to rely on ICs/internal audit, etc, etc.
Matters to consider in deciding whether to accept or continue with an engagement would, of course, be completely different.