I'm fairly certain that Premiere Pro renders all layers from bottom to top. I have found several sources that confirm this behaviour for After Effects, but nowhere is it stated explicitly for Premiere Pro.
From the Adobe documentation for After Effects:
A composition consists of layers stacked on top of one another in the Timeline panel. When the composition is rendered—either for previewing or for final output—the bottom layer is rendered first. Within each raster (non-vector) layer, elements are applied in the following order: masks, effects, transformations, and layer styles. For continuously rasterized vector layers, the default rendering order is masks, followed by transformations, and then effects.
Source
Rendering layers from bottom to top is also the logical order. If it was the other way around, blending modes and certain other effects couldn't function properly. Let's say I have two video layers, the upper one being set to multiply as it's blending mode. This blending mode takes into account the pixels of the video layer below it. This wouldn't work if that layer hadn't been rendered yet.
So I would suggest this layer order for your timeline:
Adjustment Layer with color grading effects
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Adjustment Layer with color correction effects
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Layer with video clips
Alternatively, you could just put all your LUT effects on the same adjustment layer. Keep in mind that effects on a clip are rendered top to bottom. So if you have just one adjustment layer that holds one LUT effect for color correction and another one for color grading, make sure the color correction effect is on top in the Effect Settings panel.