People don't normally include any rakeback in their winrates, although it can be calculated/approximated with tracking software.
e.g. HEM can produce stats and graphs displaying your bb/100 winrate, and then put another line on the graph which includes rakeback.
If someone says "I win at 5bb/100", then I take it to mean that is their net winnings (after rake) on the table and doesn't include any bonus payments. Occasionally someone will say "I'm on 7bb/100 after rakeback", but it's kind of pointless and disingenuous to not include those last two words if that's the case.