Hi, Danial, I used GV3101 to observe nuclear and plasma membrane localization of my protein in Nicotiana benthamiana (picture attached). My protein was ligated in binary vector pEG101 (link attached).

I grew Agrobacterium tumefaciens GV3101 overnight at 30C. I centrifuged 5mL at 4500g for 10minutes. I resuspended the pellet in water and 10mM MgCl2. Many protocols call for acetosyringone, but I've never used it. I don't use buffer. Water and 10mM MgCl2 have been sufficient to see subcellular localization. 

In answer to your questions:

1) Yes, GV3101 is suitable for N. benth and N. tobacum.

2) Suitable media is water and 10mM MgCl2. 

3) I'm not familiar with "phb-yep" vector. Is it binary? Is expression driven by 35S promoter.

http://www.indiana.edu/~pikweb/pEarleyGate%20plasmid%20vectors%20copy/Table%20of%20vectors.html