The question with regard to landline polls is do they get weighted so they reflect what the numbers would be if they included cell phones. I mean if the pollster wants their polls to be taken seriously then surely they would.
I'm not sure what you mean. Both kinds of polls are weighted to match the demographics of the electorate. The issue is more that people who answer cell phone polls but not landline polls or vice versa might vote systematically differently, even for people of the same demographic group.
Also, there are certain demographics where landline answerers might be such a tiny fraction of the population that you have to give them extremely large weights. Which doesn't necessarily bias things one way or the other, but inflates the MoE.