It depends entirely if its an NHS of non-NHS post.
If it’s an NHS post, then the terms ‘specialist’ and ‘highly specialist’ etc are linked to banding (in this case band 6 / 7 respectively). If its non-NHS they can mean anything as any organisation can set their own pay scales and career progression.
Again, when Agenda for Change came out, all roles were banded based on where they sat on the NHS KSF (Knowledge and Skills Framework) …..over time this has been used less but is a guide.
Unfortunately due to chronic underfunding, you’ll find B7’s in areas doing something a B8a will be doing in another so its hard to say explicitly. Personally, from my experience in the NHS and how I use my staff now, I wouldn’t expect a Band 6 to have line management responsibilities, or particularly even supervision responsibiltiies beyond perhaps SLTAs or students. They may have a service area they are responsible for collating evidence base for, supporting (informally) other staff members, undertaking audits etc. I would not expect formal second opinions at this level but would expect involvement in service wide projects, taking the lead with certain aspects of these. B7 therapists may have line management responsibilities, oversee or co-ordinate a larger area of service delivery, provide supervision and performance appraisals, second opinions, be involved in recruitment etc etc etc. However at this stage ultimate accountability for the service may rest with someone else….that entirely depends upon the structure of the service you are in however.
Others may disagree with me as it does vary….and again if its in the private sector these structures don’t necesserily apply or may look very different in smaller organisations…..but hope this helps?!