The relic weapons are usually only 5 ilv lower than current top-tier weapons. My guess is this patch will bring us up to i240, and then shortly after the final Alex is released we'll be able to get the relic up to 5 ilv below that, and then come the final 3.x patch, we'll be able to upgrade the relic to the same ilv as the raid weapons. There will probably be multiple steps involved (so we'll probably go from i210 to i230 and then i240 within 3.25) but I am sure the ultimate cap for the relic weapons will stay 5 ilv below raid weapons until the raid weapon ilv increases with the next raid.
ETA This is all just based on the Zeta weapon progression, and SE even admitted they messed up with this relic weapon's progression. So I doubt they're going to make people with a relic have to stay at i230 until 3.35 because at that point nobody will do the relic, because they'll never become better than the tome weapons. (Sub-stats aside.) They'll pretty much have to make people be able to hit i240 in 3.25 or else they run the risk of very few people participating in content they've released for the sake of people participating in it.
