Should be calling 'org.rockwork.Pebble.LaunchApp' - you left the Pebble out.
gdbus call -e -d org.rockwork -o /org/rockwork/B0_B4_48_62_63_F7 -m org.rockwork.Pebble.SendAppData "4dab81a6-d2fc-458a-992c-7a1f3b96a970" '{ "0": <"11:11">, "1": <"2.2">, "5": <0>, "2": <"026"> }'