When you documents are inside an array you have to use the option --jsonArray option.
However in you case I am not sure it will work because you will exceed the 16Mb size.
I suggest that you use jq to change the format of your file to something like:
{
"date" : 1 ,
"tweet" : "hello"
}
{
"date" : 2 ,
"tweet" : "world"
}
That is remove the opening and closing square brackets and the comma separating each tweet. The document structure is simple and you could also use an text editor to reformat.