You're trying to create an element using serialised text - effectively treating createElement as though it were innerHTML
innerHTML is a serialised representation of HTML as text - it's not nodes, it's just text - so you can write pretty much anything that way (providing your page is served as text/html):
cell.innerHTML += '<select id="selBidReceivedIsPM" name="selBidReceivedIsPM">'
+ '<option value="0">AM</option>'
+ '<option value="1">PM</option>';
However createElement creates individual element nodes - each <select> and <option> is a element node; the text inside each option is a text node.
So, to create the selector that way, you'd want something like this:
var selector = document.createElement('select');
selector.id = 'selBidReceivedIsPM';
selector.name = 'selBidReceivedIsPM';
var option = document.createElement('option');
option.value = '0';
option = document.createElement('option');
option.value = '1';
You could simply that though, by keeping the option data in an array and building them iteratively (with a for() loop)