To me, this is a personal preference kinda deal, unless the letter combination looks better closer or further apart.
We've used both set ups.
I've seen it both ways and have no answer if one is correct and the other not. As far as choosing, it would be, to me, a design choice depending on the font used rather than a grammatical choice.
Do not space before or after an ampersand & that is used with initials. Space once before and after an ampersand that is used to join names. P&C or Barnes & Noble is the grammatically correct way. But it really comes down to design, which one looks better, it could be different for any font.