The Chicago Manual of Style, sixteenth edition (2010) addresses this issue (somewhat obliquely) in several separate entries. Here they are:
7.81 Compound modifiers before or after a noun. When compound modifiers (also called phrasal adjectives) such as open-mouthed or full-length precede a noun, hyphenation usually lends clarity. With the exception of proper nouns (such as United States) and compounds formed by an adverb ending in -ly (see 7.82) it is never incorrect to hyphenate adjectival compounds before noun. ...
and
7.83 Multiple hyphens. Multiple hyphens are usually appropriate for such phrases as an over-the-counter drug or a winner-take-all contest. ...
and
7.85 Hyphenation guide for compounds and words formed with prefixes. ...
[Category/specific term:] phrases, adjectival [Examples:] an over-the-counter drug | a matter-of-fact reply | an up-to-date solution | sold over the counter | her tone was matter of fact | hos equipment was up to date [Summary of rule:] Hyphenated before a noun; usually open after a noun.
These various guidelines indicate to me that Chicago would favor "year-over-year growth" but "growth year over year."
When compound mod fiers (also called phrasal adjectives) such as high-profile or book-length precede a noun, hyphenation usually lends clarity. With the exception of proper nouns (such as United States) and compounds formed by an adverb ending in ly plus an adjective (see 7.86), it is never incorrect to hyphenate adjectival compounds before a noun.
Seems like you are right! I suppose this is a a "compound modifier phrasal adjective?