I don't know about other BofA card options, but the Starwood Preferred Guest (SPG) hotel loyalty program has 1:1 transfers to AGR (just without the 5K bonus per 20K transferred that comes with SPG to airline transfers). There is an SPG co-branded American Express card available and usually has an initial spending bonus in the 25K or so neighborhood.
Also, since the Marriott-SPG hotels merger, currently points can be transferred from the Marriott Rewards program to SPG at a ratio of 3 Marriott points to 1 SPG point. Chase offers a Marriott co-branded card. Also since Marriott is a Chase Ultimate Rewards (UR) transfer partner, one of the Chase UR credit cards that includes travel partner transfers as a benefit, would also allow you to eventually transfer to AGR. However the Chase options are less than ideal for daily spending compared to the SPG Amex, since the Amex effectively earns 1 AGR point per dollar, while the Chase options earn 1 AGR point per three dollars. But the (UR)--Marriott--SPG--AGR route could be useful in some situations, such as having a bunch of points you wouldn't otherwise use or depending on your alternative uses for UR/Marriott points.
A big caveat regarding SPG, is that eventually the two loyalty programs will likely be combined in some form, due to the merger. It's anyone's guess whether the SPG-style generous transfer scheme will remain...but we don't know yet when any major changes will occur so the SPG Amex would still be useful for daily AGR earning, as an alternative to the BofA AGR card, for some time to come at least.