To make the drawing of bunch grapes not so much difficult draw it .Let's see that how it can be drawn.
First start from a small round for the grape looks, because grapes are generally looks round and just flat. So make a round as it is shown in the picture no 1.
Then continue make 18 or some more rounds for the bunch of the grapes as like shown in the picture no 2
Then make its cane (shoot) with a curce line as shown in the picture no 3.
Then make another cane side for the look it as a cane as in the picture no 4.
Then make it rachis with both side by draw double line like in the picture no 6.
Then make large to the cane for the better look of the grapes as no 7
And your bunch of grapes is ready now for the color.
And after color your drawing will look like the above picture.