instead of being concerned with device breakpoints the best practice is to design for your smallest viewport first.Don't worry for portrait and landscape state , they will fit because you use min-width. and also media queries is very general and vary from case to case. you could define based on your audience how many break point you need e.g for my recent case i used this queries:
@ media (min-width:400px) larger than mobile
@ media (min-width:550px) larger than phablet
@ media (min-width:750px) larger than tablet
@ media (min-width:1000px) larger than desktop
@ media (min-width:1200px) larger than desktop HD
(based on http://getskeleton.com/#queries)
you would have break in these two point for ipad
@ media (min-width:750px) larger than tablet for portrait Ipad
@ media (min-width:1000px) larger than desktop for landscape Ipad
But if you want to design based on framework like bootstrap you could use just 3 break point , i use bootstrap always as frame work but i believe there is some limitation in design and feeling ( may some call it advantage) cause it's break sooner than user will expect, for example i have 13 inch laptop and for some website it fall into the Ipad state ( hamburger menu ) which i don't like , i think i lose the full ability in my laptop with this sort of design.
Then all is depend on amount and kind of data that you have and audience as well, if you want to design a news website, big amount data and vary user go for 3 point break because it's clean and all people can use it .
As result no worry for portrait and landscape state , they will fall into next queries.
For more explanation :