Hi,
If Tiller sync downloads a transaction to your spreadsheet, yes, you can consider it cleared by your bank (Tiller does not import any pending transactions). But - having used bank syncing for many years, (Tiller and others), the occasional transaction does get missed. Also, with one of my credit card banks there can be a discrepancy between the stated current balance and the total of cleared transactions. Tiller will pick up the balance the bank provides, and it could be incorrect until the bank processing catches up. In my Tiller sheet, I can’t use the sync process because Tiller will not support (but does allow access to) Canadian banks. So I determine my correct balances by adding up the transaction amounts, which gives you a very accurate picture. Another Tiller contributor has created a very nice formula that will keep a running balance of your transactions by bank account. I have found this very useful. You might need to add a starting balance for each account for accuracy. You can filter the tranaction sheet by Account to see the running balance in a more readable way.
You probably want to still match transactions with your on-line bank just to be sure. If Tiller would sync the Pending transactions as well, (like Quicken Simplifi does) it would be easier to build in a reconciliation process for your Tiller sheet.