I did my business taxes with turbotax and as offered a discount to do my personal taxes. Should I continue them in my business email login or with a personal email login

Most business returns are prepared using the downloaded software.  There are a few business that are available for online preparation but these are part of our Live assisted services.  Therefore, it would be a preference on your end.  

If you are preparing both returns using the downloaded software, they are separate products in most cases as business returns are prepared independently from your personal tax returns.  The only exception to filing your business returns using a different software would occur if you have a sole proprietorship or a single-member LLC, both of which would be reported on your individual return.