The majority of the commonly found London agencies from what I've seen place their WGs in Zone 1/Zone 2 Central/West London which is generally safe since they're often very tourist-packed and busy, with plenty of amenities and shops nearby.
As for AW, most of the WGs have an approximate location stated in their profile, which is normally the borough they're in. For example, if it says Kensington and Chelsea at the bottom left of the page, it's a safe assumption it will be one of the areas there such as Earl's Court or South Kensington (feel free to check Google maps that tell you these areas fall under to get an idea for your commute). Likewise, if it says City of Westminister, then it might be Victoria or Pimlico. Both these examples are usually safe and quite central.
As always, you still need to be street smart because no area of London is immune to crime. Even if it's something like moped thieves doing phone snatching, just be aware of your surroundings and stay in busy areas imo.
