"Excuse me, where is the bathroom?"
Translation:Entschuldigung, wo ist die Toilette?
What was the sentence you wrote? There are accepted alternatives that use das Badezimmer.
The difference is that die Toilette is the toilet (the actual fixture that you sit on to do your business) or, by extension, a room with a toilet in it, while das Badezimmer is a room for taking a bath in -- it may include a shower or a bathtub, but may or may not have a toilet in it.
Some homes have separate rooms for showering and for the toilet, so if you want to use the toilet, asking for das Badezimmer may not get you what you want.
What does "wie bitte" mean?
It's used when you didn't hear what someone said and you would like them to repeat what they said.
It's not used as a polite way to start a question.
So in that sense, it doesn't "mean" "excuse me" -- it isn't used everywhere that "excuse me" is used in English, but only in some of the situations.