In short the RA bonuses and interest are ring fenced from the ERS limit.
This is a 'special year' if you were at the old ERS, from next year the RSTU will be back to $10,500 or so I expect. This is also a special year in which you could, if you have the wherewithal, boost your total CPF by a full BRS amount in cash (rather than an OA > RA transfer).
If you're really keen to boost RA, you could theoretically (before mid Jan) pay in a full VC as well - that hits the SA which means it would go into your RA in mid Jan.