I noticed on flightaware.com that the first two flights from BDL to DTW parked at gates A21 and A33 respectively; A21 is very close to the escalator up to the tram which runs above the concourse and stops in the middle and at the north end (where the A 60s and 70s gates are). Both SAN flights this morning used A76. Including walk time, your trip between gates will not take more than 10-12 minutes. So you should be OK.