cust_nodes = [n for n in G.nodes() if G.nodes[n]
                 ['bipartite'] == 'customers']
prod_nodes = [n for n in G.nodes() if G.nodes[n]
                 ['bipartite'] == 'products']

mat = nx.bipartite.biadjacency_matrix(G, 
          row_order=cust_nodes, column_order=prod_nodes)

mat

<3x2 sparse matrix of type '<class 'numpy.int64'>'
with 3 stored elements in Compressed Sparse Row format>