Frasier makes the comment that Portia is Bebe's "flying monkey." Interestingly, Kristin Chenoweth played Glinda "the good witch" in the Broadway production of "Wicked," whose story serves as a prequel to "The Wizard of Oz (1939)."
The building visible from Frasier's agent's window is Chicago's Brewster Building, which also appears in the movie "Child's Play" and in "The Drew Carey Show."
The celebrity callers in this episode are Cherry Jones (Polly) and Pat Boone (Garth). Polly calls in while Frasier (Kelsey Grammer) and Kenny (Tom McGowan) are arguing over the show's advertising budget after Dr. Zach's (Chris Berg) more sexually oriented show begins dominating the ratings. When Garth calls in, he mentions he's part of a couple with problems, Kenny and Frasier get their hopes up anticipating a juicy call, only to find out Garth has called in for advice regarding budget problems.
Frasier takes the station manager Kenny to his exclusive club to play some squash, The Rainier Club. The club is located on 4th between Columbia and Marion. It is a top level, private club for members only: it is certainly the type of club Frasier would insist on being a member of. However, The Rainier Club does not offer courts for play: that would be available at the Washington Athletic Club, located on 6th. However, most likely The Rainier Club is used with a little license taken to add the play courts.
Based on the architecture and lack of tall buildings in the distance, Bebe's office view would indicate her office Is approximately located at 1st or 2nd around Cherry or Columbia. This would be right on the Northern boundary of Seattle's Pioneer Square district and just a few blocks north of the likely location of Cafe Nervosa.