In late 1998, I requested that my IRA trustee convert the entire balance of my IRA to a Roth IRA. The distribution from my IRA was effected 12/30/98 and reported on a 1998 Form 1099-R. The trustee established a Roth IRA account for by benefit on 12/30/98. However, the rollover to the Roth IRA was not effective until 1/14/99. I did not receive a 1998 Form 5498 (IRA Contribution Information) from the trustee with respect to the Roth IRA account.

Does this conversion allow me to use the four-year income reporting method?

You can use the 4 year income spread. The only issue for you is whether 1998 or 1999 counts as the first year for computing when the account is more than 5 years old.