Useful picture. You will see that the bed is curved slightly in towards the middle. That is a deliberate design feature, especially if you have the fitted legs (I don't) so you can get your body much closer to the centre line, which means you lean over much less and its easier on your body for long sessions. My bench is long and narrow, if it were like Skeetster's above I would try to bring the lathe as far forward on the bench as possible. I know you can rotate the head for hollowing but you inevitably need to lean in for some things.
A 'rule of thumb' for determining bench height is to stand facing the headstock with your finger on the (not running) spindle, If your elbow is at right angles it is 'about right'' for most people. Some have different preferences but it works for me. You can see what you are doing but you are not leaning over so much it strains your back in prolonged use. So, stand by a wall, point at it with your elbow at 90 degrees, measure how far off the floor your finger is, find the lathe specs and work out how high the bench needs to be to get the centre line at that height. On the Coronet Herald with bench feet, its about 320mm from the bottom of the bench feet to the centre line.