Frameworks in personal portfolio?

Think it would be fine as long as you are not being deceptive about it. Having examples of your work from scratch and using frameworks would show your broad range of skills.

In interview, if asked about your choice of using framework, you can cite specific reasons you like and use it.

You see many jobs for developers that list specific frameworks - like this one: http://www.dice.com/job/result/10529944/517965?src=54&q=bootstrap

I'd say that primarily depends on how you plan to use the framework of your choice. Are you going to customize it significantly? Will people be able to say "That's Bootstrap!" at a glance?

I think there's a lot of space for someone to show off their skills while customizing a framework. If done elegantly and with planning, it shows off your ability to work with an existing codebase. I've seen some amazing things done in both Bootstrap and Foundation, sites that you'd never guess were using a framework until you viewed their source code.

Keep in mind one thing, though. Both of those frameworks were made for projects that really need most of those components that they include. Does your portfolio need all of that? Alerts? Modals? Orbit slider and whatnot?

Also, when using a framework like Bootstrap, a lot of people opt to use default Bootstrap/Foundation classes in their HTML which produces an unreadable mess in the code. Whatever you end up using, keep in mind that a more semantic markup is desired. Use the built-in LESS/SASS mixins to create your own elements, ones that make sense (e.g. Instead of a .col-sm-9 or whatever it's called, use a mixin to create your own class with that does the same thing but is maybe called .projects). This may seem unimportant, but it really shows if you understand the point of a framework.

In my experience, most portfolio sites only need a decent grid system. If you find yourself redesigning every element of Bootstrap/Foundation, why did you use it in the first place? It would've been easier to style all the components you need on your own.

The best thing you can do is put on paper everything that your portfolio site is going to contain. Then figure out what elements you need to display all of that. If you really need the majority of what a framework offers, then proceed with a framework. Otherwise...

Well, there are middle-ground options. You don't need to code from scratch, but you also don't need a large framework. Take a look at a nice grid system like Bourbon Neat, or maybe a set of nice modules like Pure. Bootstrap and Foundation are not the only players, and some of the smaller frameworks are a far better choice for a portfolio-like project.

Personally, I use Foundation and Bootstrap when building full-fledged web apps, when I know that I'll need most of their components. If I'm making a simple site, I usually end up writing from scratch, leveraged by Compass or Bourbon with a nice little grid system.