The RCM theory syllabus, as keypeg mentioned above, is available online. This outlines the official exam requirements.
I think of the Wharram book as the user manual for RCM rudiments. Personally, I've found it useful, but some students might feel overwhelmed by all the information in it.
Some other resources to consider:
Boris Berlin, Four Star Sight Reading and Ear Tests. It is a graded series, so only relevant material for the level in each book.
Bennett and Capp, Complete Series of Sight Reading and Ear Tests. It's a graded series.
For ear training, in addition to practising with exam questions, I would recommend improvising at the keyboard with intervals and simple melodies. Getting familiar with the keyboard and how to improvise simple melodies, will be good preparation for the melody playback questions.
Try to make developing ear training a daily activity in music making, and not just an academic exercise in being able to answer an exam question. For example, try to playback the tune you hear in a TV jiingle. A phone rings in the room, try to playback the ringtone. Clap back the rhythm you hear construction workers making with their tools. Get out some paper and try to notate that same rhythm. Find ways to involve ear training in daily activities.