Roy, João,
Generally the servants were berthed in separate rooms. The Allison's maid & nurse seem to have been berthed with Trevor. - If you look at The Cave List, you will see the Mrs Spencer's maid was in one of the so-called Servant's Cabins on B-deck close to her employers. Mrs White's servants were some distance away in C-99/1 and C-120/1. - Mrs White was in C-32. - Mrs Hays' maid was in B-24. Mr & Mrs Hays in B-69. Lady Duff-Gordon's maid was on E-deck. The Spedden servants were in adjoining rooms. Mrs Peñasco y Castellana's maid was across the passageway. - In most cases no room numbers are given, but Mrs Douglas who was in C-86 noted that her maid shared a room with Mrs Carter's maid. The Carters were in B-96/98. From the testimony of steward Etches we know the Carter manservant was in B-86. Miss Allen said that her aunt, Mrs Robert's maid was on E-deck.
João,
With the exception of the Carter servants, all of the other servants [other than those traveling on 2nd Class tickets] were as far as I am aware on the same ticket as that of their employer. - You can check the ticket numbers for yourself by looking at the names.
I hope that gives an idea. Some servants were nearby, other were berthed decks below.