The paint looks good.
They make pre-stain treatments that can help prevent large contrasts between the hard and soft grains of the wood, and also help with blotching. I think the biggest factor is the species of wood, and perhaps, to a lesser degree, technique (wiping the stain on with the grain, consistency with hold times, and blending the color as you wipe it off).
I had very little wood finishing experience and managed to get fairly even results with the Okoume I'm using, but it is very uniform. The biggest problem I had with my relatively dark red chestnut color was the fact that towards the end of a can some of the darker pigments would settle and clump at the bottom of the can, then they didn't want to stir back in again; so I ended up with some panels that appear slightly lighter than others with a hint of pink.
I think it was Aggie79/Tom who suggested that you can tint oil based poly with oil based stain to mute down the blotches some.
Regardless, that is water over the dam. Like I said, your paint looks good.
