The pattern doesn't explicitly state when to switch to larger needles

I am used to patterns that tell me explicitly, “now switch to the larger needles” when the pattern requires two different size needles. This pattern, the beautiful Paloma Sweater by Espace Tricot, does not.

Am I supposed to switch to my larger needles where at the yoke? Or is the yoke part of the neck ribbing?

That is a beautiful sweater.
It’s easy to miss but right under tools the pattern recommends:
“For neck ribbing:
16” circular needles: 4 mm (US 6) – or one size smaller than gauge needle.
For rest of sweater (including body, cuffs, and hem):
16”, 24”, and 32” circular needles: 4.5 mm (US 7) – or size needed to obtain gauge”

The neck ribbing is at the beginning of the sweater. Four inches of p1, k1tbl around the neck on the smaller needle. Once that’s complete, change to main gauge needle (the larger needle) for the rest of the sweater starting at the marker set up round.

I had to read that portion of the pattern, a couple of times. You switch to the larger needles after the yoke. The smaller needles are for the neck ribbing and yoke.