Spring Avenue of Trees

8x10 Oil on canvas.  This has an under painting of acrylic with oil on top.  Does anyone know if this is a bad thing to do?  I read in a book that you are not supposed to put acrylic under oil, but I've also read that it's okay.  Only time will tell if it is going to crack.  I wanted a dreamlike feel to the painting, but I think it turned out kind of eerie because of the dark shadows juxtaposed to the bright yellows, oranges, and greens.