Note - nothing was referenced specifically in the Autumn Spending review in the same way as HS2. Other major projects were also detailed at a lesser cost, at 6bn I would have expected this to have appeared.
Bagso, work on any of the relevant transport schemes is unlikely to start in the current spending review period (i.e. to 2020/21) it should therefore not come as a surprise that it wasn't referenced by the Chancellor. Work on HS2 will start and the next steps in relation to the later phases (i.e. to Manchester and Leeds) will start their parliamentary journey in the lifetime of the current government - hence the overall funding envelope for the project being confirmed in the Autumn Statement.