<?php

$array = array();

$id = "meu_id";

$nomes = ["Aluguel", "Água", "Contabilidade", "Energia",
          "Imposto", "IPTU",  "Marketing"   , "Telefone"]; 

$max = count( $nomes );

for( $count = 0; $count < $max; $count++) 
{
    $array[$count] = array(
        'id_assinante' => $id,  
        'nome' => $nomes[$count] );  
}
var_dump($array);