Can we use Database Transactions like this?

Hello,

In CI user guide, i only see using $this->db->query() method, are we also allowed to use "Active Record Class" like this?

PHP Code:

$data_balance = array(
 'balance' => $newbalance
);          
$data_transaction = array(
 'amount' => $amount,
 'user' => $user
); 


PHP Code:

$this->db->trans_start();
 // This is an "Insert" query for a table
 $this->db->set('date', 'NOW()', FALSE);
 $this->db->insert('financial_transactions', $data_transaction);
 // This is an "Update" query for another table
 $this->db->where('user_id', $user_id);
 $this->db->update('financial_balances', $data_balance);
$this->db->trans_complete(); 


PHP Code:

if ($this->db->trans_status() === FALSE){
    // Do stuff if failed 
} 


Note that i use $this->db-> for both queries, so i don't know if the success result of first one is actually cleared to check the second one?

Is this going to work? can i trust that this will make either both queries to success or neither of them (i don't want one to success and one to fail)