I worked from home for seven years, and am doing so again as a contractor after a brief stint in an office that didn't work out (less than a month).

Having two machines made sense for me, along with two phones, but as a compromise two logins would work. The appeal of two hosts is that you do have the chance to write one off, or have it be provided/maintained by your employer.

I always used a KVM so I could only physically control one host at a time, but I guess you get the same clean separation if you used different logins.