What is maximum frequency of ADG506 Multiplexer?
Page 8 defines tTRANSITION as "Delay time between the 50% and 90% points of the digital inputs and switch “ON” condition when switching from one address state to another". In order words, this parameter only affects switching between channels, not the analog signal on either one.

The bandwidth of the analog signal is affected by RON and the input capacitance of the next stage, both of which limit the slew rate of the signal.