Procedure to restore Bitcoin Core backup
If you are using bitcoin 0.15.1, it will be using a HD (hierarchical deterministic) wallet by default. This means that all addresses it uses are generated from a single master key in a deterministic way. That means that even addresses you generate after the backup will still be recoverable, as will any transactions sent to them. The exception would be if you upgraded to a new wallet version which supported address types that 0.15.1 didn't (at some point in the future), in which case if you send funds to those address types 0.15.1 might not recognize them (although the private keys can probably still be recovered from your HD wallet