Typically, if substitutes are not required to pay any fees for the week they bowl, they will appear on the team roster on the Weekly Fees page for that week only, but will be removed on the following week. However, once a payment is made by the bowler listed as a substitute, they will always appear with the team which the payment was made. Theoretically, they could be a part of every team's financial history. In the same way, bowlers that quit will always be displayed (assuming they made any payments) as will Teams that are dropped (they are part of the League's financial history).
Note: If you enter a payment for a substitute, and later come back and remove that payment from the record, the internal flag has already been set that the substitute is a member of that Team's financial history and they will always be displayed with that team.