Ancestry.com has a marriage record ($) for Alois Bauch (marriage to Selma Günther on 28 March 1905). A side note lists only one son, born 1907 (number 160/1907 Wilmersdorf), who married in 1940 in Wilhelmshaven (number 455?/1940). If city directories don’t list the family later than 1922, it is possible that Alois Bauch either died (and his wife is listed then) or the family moved.
I could not find a death certificate for Alois Bauch. What is listed there, depends on when the certificate was issued. It is unlikely that his (whole) family would be listed there. Sometimes the family member who reported the death is named.
Digitized name indices are available from Landesarchiv Berlin, you can search them by register office and type of record.
Furthermore you can request information from the Einwohnermeldekartei on family members from the Landesarchiv, but wartime losses are likely.
You could try to get the birth certificate for his wife, Selma Günther, who was born in Staßfurt 4 June 1877 and see if you can trace her death certificate and thus her whereabouts in later years.
Update 3 March 2017
The birth certificate is not available from Ancestry, as their collection on Berlin birth records spans only the period form 1874 to 1899. As the son was born in 1907 his birth records should be available from the Landesarchiv (state archiv) after 2017 (after 110 years). Until then Bezirksamt Charlottenburg-Wilmersdorf should have the birth records. You can request a copy („nicht-beglaubigte Kopie mit allen Randvermerken“) from them for a fee. Don’t ask for a birth certificate, as they might provide you a modern printout with only limited data. Access restrictions might apply, it certainly helps to outline your relationship and to tell them when your uncle died (if known). If they don’t grant you a copy you have to wait until it is handed over to the archives and other rules apply.