can you get a loan for a house if the land is worth more then 2/3 of the house appraisal

Yes, but it really depends on the type of property overall. There are ocean front properties that sit on very small parcels of land with a cottage and the house is worth only a fraction of the land, so it is a case by case basis.

Yes, an appraisal values the land and house together, based on the limited info you provided