How to handle multisyllable/multiword ruby annotations in Chinese

In the examples shown in clreq all the word-based annotations, such as píngshéng or xiàohuà, have no space between the syllables. Is this always the case, or do you sometimes see the pinyin for a word as two (or more) syllables with space between?

The example that includes Kieth Emerson seems to attach those two names to separate runs of hanzi characters.

Are there cases (and presumably there are for bilingual annotations or interlinear comments) where more than one latin script word is included in a single annotation, with a space between? If such an annotation is short and appears over a long base text, what happens to the words?

Here i'm modifying the Keith Emerson example to show what i mean. There's a lot of base character width, and much less annotation width, and the one annotation includes two words.

Should they be set solid and centred like this:

Or should they be like the CSS space-around setting (leaving a large gap in the middle) (this is Firefox's default):

(I'm assuming that it would be wrong to equally space all the characters across the ruby text box, as you would for hanzi annotations.)