Here are a data fact sheet from PWC China :
1) Foreigners participating in the social security scheme will receive social security cards and can enjoy benefits similar to those of local Chinese. For example, the number of years of pension contribution by foreigners can be aggregated if they return to work in mainland China again after their previous employment in mainland China. Foreigners are entitled to monthly pension payout after retirement if certain criteria (i.e. minimum contribution years) are satisfied, or the cumulative balance of individual social security account can be withdrawn upon written application for termination by the foreigners.
2) While it is indicated that foreigners participating in the Chinese social security scheme should be entitled to benefits similar to those enjoyed by local Chinese, The Provisional Measures do not elaborate on how foreigners could apply / enjoy the benefits except for
pension.

I don't know if the link will work or not and for how long. Anyway, I kept a copy of the document, so if someone needs it, just send me an email.